Mock Exam 15
MRCOG Part 1 — Simulated Paper 2
100 mixed SBA (single best answer) and MBA (multiple best answer) questions simulating MRCOG Part 1 Paper 2. Covers all syllabus topics proportionally. Includes detailed explanations.
Q1 [SBA] (Anatomy — Abdominal wall) — A 45-year-old woman undergoes a transverse supraumbilical incision for ovarian cystectomy. Which of the following correctly describes the blood supply to this region of the anterior abdominal wall? A) Superior epigastric artery, a terminal branch of the internal thoracic artery B) Inferior epigastric artery, a branch of the external iliac artery C) Superficial circumflex iliac artery, a branch of the femoral artery D) Deep circumflex iliac artery, a branch of the external iliac artery E) Posterior intercostal arteries from T7–T12
Answer: A
The superior epigastric artery is the terminal branch of the internal thoracic artery and supplies the supraumbilical abdominal wall. The inferior epigastric artery supplies the infraumbilical region. A supraumbilical incision therefore relies primarily on the superior epigastric artery for its blood supply.
Q2 [MBA] (Anatomy — Perineum) — A 32-year-old woman sustains a third-degree perineal tear during vaginal delivery. Which of the following structures may be involved in a complete third-degree tear? Select ALL that apply. A) External anal sphincter B) Internal anal sphincter C) Rectal mucosa D) Perineal body E) Puborectalis muscle
Answer: A, B, D
A third-degree perineal tear involves the perineal body and the anal sphincter complex (external and internal anal sphincters). A fourth-degree tear extends through the rectal mucosa. The puborectalis is part of the levator ani and is not typically involved in perineal tears classified by degree.
Q3 [SBA] (Reproductive Physiology — Parturition) — A 29-year-old primigravida at 40+3 weeks' gestation is in the active phase of labour. Cervical examination shows 5 cm dilation, 80% effacement, and the presenting part at station 0. Which of the following physiological events is the primary driver of progressive cervical dilation during this phase? A) Uterine fundal dominance with coordinated contractions B) Ferguson reflex triggered by fetal head descent C) Release of prostaglandins from the amnion and chorion D) Contraction of the lower uterine segment E) Relaxin-mediated softening of cervical collagen
Answer: A
In the active phase of labour, uterine fundal dominance — where the fundus contracts more strongly than the lower segment — creates a pressure gradient that gradually pulls the cervix upward over the presenting part. This mechanical action, combined with uterine contractions, is the primary driver of progressive cervical dilation. Prostaglandins contribute to cervical ripening but are not the primary driver during active dilation.
Q4 [SBA] (Endocrinology — Adrenal) — A 34-year-old woman presents with hirsutism, acne, oligomenorrhoea, and hypertension. Investigations show: serum cortisol 850 nmol/L (normal < 500), ACTH 55 pg/mL (normal 10–50), urinary free cortisol 350 µg/24h (normal < 100). A low-dose dexamethasone suppression test fails to suppress cortisol. High-dose dexamethasone suppresses cortisol by 60%. Which of the following is the most likely diagnosis? A) Adrenal adenoma B) Cushing's disease C) Ectopic ACTH syndrome D) Adrenal carcinoma E) Pseudo-Cushing syndrome
Answer: B
The elevated ACTH with cortisol excess suggests ACTH-dependent Cushing syndrome. Suppression with high-dose dexamethasone (by >50%) characteristically occurs in Cushing's disease (pituitary microadenoma) but not in ectopic ACTH syndrome or adrenal tumours. Adrenal adenomas would show low ACTH with autonomous cortisol production.
Q5 [MBA] (Fetal/Neonatal Physiology — Jaundice) — A term neonate develops jaundice at 36 hours of life. Total serum bilirubin is 280 µmol/L. Which of the following factors increase the risk of bilirubin-induced neurotoxicity? Select ALL that apply. A) Gestational age 40 weeks B) Albumin 25 g/L C) Sepsis D) Breastfeeding E) Haemolysis
Answer: B, C, E
The risk of bilirubin-induced neurotoxicity (kernicterus) is increased by factors that reduce bilirubin-albumin binding or increase free bilirubin: hypoalbuminaemia (<30 g/L), sepsis (displaces bilirubin from albumin), and haemolysis (rapidly rising unconjugated bilirubin). Gestational age 40 weeks is protective compared to prematurity, and breastfeeding alone without significant dehydration is not a major neurotoxicity risk factor.
Q6 [SBA] (Pathology — Ovarian tumours) — A 55-year-old postmenopausal woman presents with abdominal distension and bloating. CA-125 is 450 U/mL. CT scan shows a complex ovarian mass with solid and cystic components and peritoneal deposits. Histology shows a tumour with psammoma bodies, serous cell type, and a WT1-positive immunoprofile. Which of the following is the most likely diagnosis? A) Mucinous cystadenocarcinoma B) High-grade serous ovarian carcinoma C) Clear cell carcinoma D) Endometrioid carcinoma E) Granulosa cell tumour
Answer: B
High-grade serous ovarian carcinoma (HGSOC) is the most common epithelial ovarian malignancy. It is characterised by psammoma bodies, WT1 positivity, and typically presents at an advanced stage with peritoneal carcinomatosis. Mucinous tumours are usually WT1-negative and CA-125 may be less elevated. Clear cell and endometrioid carcinomas are associated with endometriosis and have different immunoprofiles.
Q7 [SBA] (Pharmacology — Contraceptives) — A 24-year-old woman with a history of migraine with aura requests a reliable contraceptive method. Her BMI is 22 kg/m², she is a non-smoker, and has no other medical comorbidities. Which of the following is contraindicated in this patient? A) Copper intrauterine device B) Progesterone-only pill C) Combined oral contraceptive pill D) Etonogestrel implant E) Levonorgestrel intrauterine system
Answer: C
Migraine with aura is a UKMEC 4 condition for combined hormonal contraception (CHC) due to an increased risk of ischaemic stroke. The UKMEC states that CHC should not be used in women who have migraine with aura at any age. Progesterone-only methods (pill, implant, IUS) and copper IUD are safe alternatives as they do not increase stroke risk.
Q8 [SBA] (Microbiology — TORCH) — A 26-year-old woman at 18 weeks' gestation is found on routine screening to have elevated IgM antibodies to Toxoplasma gondii. IgG avidity testing shows low avidity. She is asymptomatic. Which of the following is the most appropriate next step? A) Repeat serology in 4 weeks B) Start spiramycin immediately C) Start pyrimethamine-sulfadiazine immediately D) Perform amniocentesis for PCR E) Offer termination of pregnancy
Answer: B
Low IgG avidity confirms recent primary infection (<12-16 weeks). In the first and early second trimester, spiramycin is recommended to reduce the risk of vertical transmission. Amniocentesis for PCR is offered after 18 weeks to confirm fetal infection. Pyrimethamine-sulfadiazine is used if fetal infection is confirmed. Spiramycin does not cross the placenta significantly and is used for maternal treatment.
Q9 [SBA] (Immunology — Anti-phospholipid) — A 32-year-old woman with a history of three first-trimester miscarriages and a previous deep vein thrombosis is diagnosed with antiphospholipid syndrome (APS). Which of the following laboratory findings is most specific for the diagnosis? A) Positive antinuclear antibody (ANA) B) Prolonged activated partial thromboplastin time (aPTT) that corrects with mixing C) Positive lupus anticoagulant on two occasions 12 weeks apart D) Elevated erythrocyte sedimentation rate E) Positive anti-dsDNA antibody
Answer: C
The diagnosis of APS requires at least one clinical criterion (vascular thrombosis or pregnancy morbidity) and at least one laboratory criterion (lupus anticoagulant, anticardiolipin IgG/IgM, or anti-β2 glycoprotein-I IgG/IgM) present on two or more occasions at least 12 weeks apart. Lupus anticoagulant is the most specific test. The aPTT in APS does NOT correct with mixing (inhibitor), whereas coagulation factor deficiencies do correct.
Q10 [MBA] (Biochemistry — Tumour markers) — Which of the following tumour markers are correctly paired with their associated gynaecological malignancy? Select ALL that apply. A) CA-125 — Epithelial ovarian carcinoma B) AFP — Ovarian yolk sac tumour C) hCG — Granulosa cell tumour D) Inhibin B — Mucinous ovarian tumour E) LDH — Dysgerminoma
Answer: A, B, E
CA-125 is elevated in epithelial ovarian carcinoma (particularly serous). AFP is elevated in yolk sac tumours (a type of germ cell tumour). LDH is elevated in dysgerminomas. hCG is associated with choriocarcinoma and germ cell tumours, not granulosa cell tumours. Inhibin B is elevated in granulosa cell tumours, not mucinous tumours.
Q11 [SBA] (Genetics — BRCA) — A 38-year-old woman of Ashkenazi Jewish descent is found to have a BRCA1 mutation after her sister was diagnosed with ovarian cancer at age 48. Which of the following best describes the inheritance pattern and penetrance of BRCA1 mutations? A) Autosomal recessive with 90% penetrance for breast cancer by age 70 B) X-linked dominant with 60% lifetime risk of ovarian cancer C) Autosomal dominant with incomplete penetrance for breast and ovarian cancer D) Autosomal dominant with complete penetrance for breast cancer E) Mitochondrial inheritance with maternal transmission only
Answer: C
BRCA1 and BRCA2 mutations are inherited in an autosomal dominant pattern with incomplete penetrance. The lifetime risk of breast cancer with BRCA1 mutation is approximately 65-80% and ovarian cancer 40-50% by age 70. Not all carriers develop cancer (incomplete penetrance), and expression varies with other genetic and environmental factors. The inheritance is not recessive, X-linked, or mitochondrial.
Q12 [SBA] (Embryology — Congenital anomalies) — A newborn male is diagnosed with prune belly syndrome. Which of the following embryological events is most likely to have been disrupted? A) Failure of the urogenital sinus to divide B) Abnormal mesonephric duct development C) Defective development of the abdominal wall musculature with urinary tract abnormalities D) Failure of cloacal membrane rupture E) Persistent urachus
Answer: C
Prune belly syndrome (Eagle-Barrett syndrome) is characterised by partial or complete absence of the abdominal wall musculature, bilateral cryptorchidism, and urinary tract anomalies (dilated ureters, dilated bladder, renal dysplasia). The underlying cause is thought to be early urethral obstruction leading to massive bladder distension in utero, causing both abdominal wall muscle deficiency and testicular maldescent.
Q13 [SBA] (Statistics — NNT) — A randomised controlled trial investigates a new tocolytic agent for preventing preterm birth before 34 weeks. The incidence of preterm birth in the control group is 25% and in the treatment group is 15%. What is the number needed to treat (NNT)? A) 5 B) 10 C) 15 D) 20 E) 25
Answer: B
The absolute risk reduction (ARR) = control event rate − treatment event rate = 0.25 − 0.15 = 0.10. NNT = 1/ARR = 1/0.10 = 10. This means 10 women need to be treated with the tocolytic agent to prevent one additional preterm birth before 34 weeks.
Q14 [SBA] (Clinical/Surgical — Instruments) — During a diagnostic laparoscopy, a 5-mm trocar is inserted at the umbilicus. After establishing the pneumoperitoneum, a second 5-mm port is placed in the left iliac fossa. Which of the following instruments is most commonly used for peritoneal biopsy through a 5-mm port? A) Maryland dissector B) Endoscopic scissors C) Biopsy forceps (5-mm cup forceps) D) Harmonic scalpel E) Laparoscopic Babcock forceps
Answer: C
Cup biopsy forceps (5 mm) are designed specifically for obtaining tissue samples through laparoscopic ports. They have serrated jaws that allow a clean bite of peritoneum or ovarian capsule. Maryland dissectors are for tissue dissection and grasping. Endoscopic scissors are for cutting. The harmonic scalpel is for coagulation and cutting. Babcock forceps are atraumatic graspers.
Q15 [SBA] (Anatomy — Surgical anatomy) — During a total abdominal hysterectomy, the ureter is at greatest risk of injury at which of the following points? A) At the pelvic brim where it crosses the common iliac artery bifurcation B) Where it passes under the uterine artery ("water under the bridge") C) Where it enters the bladder trigone D) At the infundibulopelvic ligament E) Where it crosses the obturator fossa
Answer: B
The ureter is at greatest risk of injury during hysterectomy where it passes beneath the uterine artery approximately 1.5–2 cm lateral to the cervix — the classic "water under the bridge" relationship (water = ureter, bridge = uterine artery). This is where ligation of the uterine artery during hysterectomy can inadvertently incorporate the ureter. The ureter is also at risk at the pelvic brim during ovarian vessel ligation.
Q16 [MBA] (Anatomy — Nerve injuries) — During a McRoberts manoeuvre for shoulder dystocia, a 32-year-old woman develops postpartum foot drop and loss of sensation over the anterior and lateral thigh. Which of the following nerves may have been injured? Select ALL that apply. A) Femoral nerve B) Obturator nerve C) Sciatic nerve D) Lateral femoral cutaneous nerve E) Common peroneal nerve
Answer: A, D
McRoberts manoeuvre involves extreme flexion of the thighs onto the abdomen, which can cause compression of the femoral nerve (L2–L4) and lateral femoral cutaneous nerve (L2–L3) against the inguinal ligament. Femoral nerve injury presents with hip flexion weakness and sensory loss over the anterior thigh. Lateral femoral cutaneous nerve injury causes meralgia paraesthetica (sensory loss over lateral thigh). The obturator and sciatic nerves are less commonly injured in this manoeuvre.
Q17 [SBA] (Reproductive Physiology — Lactation) — A 30-year-old woman who is exclusively breastfeeding her 4-week-old infant reports painful, engorged breasts with cracked nipples. Which of the following correctly describes the neuroendocrine reflex responsible for milk let-down? A) Suckling stimulates prolactin release from the posterior pituitary B) Suckling stimulates oxytocin release from the anterior pituitary C) Suckling stimulates oxytocin release from the posterior pituitary via a hypothalamic reflex D) Prolactin from the posterior pituitary causes myoepithelial cell contraction E) Oxytocin from the anterior pituitary stimulates alveolar milk secretion
Answer: C
The milk let-down (ejection) reflex is mediated by oxytocin, which is synthesised in the paraventricular and supraoptic nuclei of the hypothalamus and released from the posterior pituitary. Suckling stimulates afferent neural signals to the hypothalamus, triggering pulsatile oxytocin release. Oxytocin causes contraction of myoepithelial cells surrounding the alveoli, forcing milk into the lactiferous sinuses. Prolactin (from the anterior pituitary) is responsible for milk synthesis, not ejection.
Q18 [SBA] (Endocrinology — Calcium) — A 28-year-old woman with a history of thyroidectomy 6 years ago presents with tetany and paraesthesia. Serum calcium is 1.8 mmol/L (normal 2.2–2.6), phosphate 1.6 mmol/L (normal 0.8–1.45), and PTH is undetectable. Which of the following electrolyte abnormalities would most likely be present on ECG? A) Shortened QT interval B) Prolonged QT interval C) Peaked T waves D) U waves E) ST segment elevation
Answer: B
This patient has hypocalcaemia due to iatrogenic hypoparathyroidism (post-thyroidectomy). Hypocalcaemia prolongs the QT interval on ECG because calcium is required for normal cardiac repolarisation. Shortened QT interval is seen in hypercalcaemia. Peaked T waves suggest hyperkalaemia. U waves are associated with hypokalaemia.
Q19 [SBA] (Fetal/Neonatal Physiology — Respiratory) — A preterm neonate born at 28 weeks' gestation develops respiratory distress syndrome. Which of the following correctly describes the composition and function of pulmonary surfactant? A) Primarily composed of surfactant protein A and cholesterol B) Dipalmitoylphosphatidylcholine (DPPC) reduces surface tension at the air-liquid interface C) Surfactant is secreted by alveolar macrophages D) Surfactant production begins at 24 weeks and reaches mature levels at 30 weeks E) The lecithin:sphingomyelin ratio decreases with lung maturity
Answer: B
DPPC (a phospholipid) is the primary surface-active component of surfactant. It reduces surface tension at the air-liquid interface, preventing alveolar collapse at end-expiration. Surfactant is secreted by type II pneumocytes, not macrophages. Production begins at 20-24 weeks but only reaches adequate levels after 34-36 weeks. The lecithin:sphingomyelin (L/S) ratio increases with lung maturity; an L/S ratio >2 indicates fetal lung maturity.
Q20 [SBA] (Pathology — Cervical pathology) — A 35-year-old woman undergoes cervical screening. The result shows high-grade squamous intraepithelial lesion (HSIL). A colposcopy-directed biopsy reveals CIN 3. Which of the following p16 immunohistochemistry patterns is most consistent with this diagnosis? A) Diffuse block-positive p16 staining B) Focal patchy p16 staining C) Negative p16 staining D) Cytoplasmic p16 staining only E) Nuclear p16 staining only
Answer: A
In high-grade CIN (CIN 2/3), p16 immunohistochemistry typically shows diffuse block-positive staining (continuous staining of the full thickness or lower 2/3 of the epithelium). This reflects high-risk HPV E7-mediated RB pathway inactivation leading to p16 overexpression. Focal or patchy staining is more suggestive of reactive changes or low-grade lesions. p16 is a surrogate biomarker of HPV-related oncogenesis.
Q21 [MBA] (Pharmacology — Chemotherapy) — A 48-year-old woman with high-grade serous ovarian carcinoma is scheduled for neoadjuvant chemotherapy with carboplatin and paclitaxel. Which of the following are known mechanisms of action or toxicities associated with these drugs? Select ALL that apply. A) Carboplatin crosslinks DNA, inhibiting replication B) Paclitaxel stabilises microtubules, preventing depolymerisation C) Carboplatin causes dose-limiting nephrotoxicity D) Paclitaxel causes dose-limiting peripheral neuropathy E) Both drugs are cell cycle phase-specific agents
Answer: A, B, D
Carboplatin is a platinum analogue that forms DNA crosslinks, inhibiting replication and transcription. Paclitaxel (a taxane) stabilises microtubules by preventing depolymerisation, causing mitotic arrest. Carboplatin's dose-limiting toxicity is myelosuppression (thrombocytopenia), not nephrotoxicity (that is cisplatin). Paclitaxel causes dose-limiting peripheral neuropathy. Carboplatin is cell cycle phase-nonspecific; paclitaxel is M-phase specific.
Q22 [SBA] (Microbiology — HIV) — A 34-year-old HIV-positive woman presents at 12 weeks' gestation for antenatal booking. Her CD4 count is 480 cells/µL and viral load is 350 copies/mL. She is currently not on antiretroviral therapy. Which of the following is the most important intervention to reduce vertical transmission? A) Start zidovudine monotherapy in the third trimester B) Start triple antiretroviral therapy immediately C) Delay antiretroviral therapy until the second trimester to avoid teratogenicity D) Plan elective caesarean section at 38 weeks regardless of viral load E) Advise exclusive formula feeding from birth
Answer: B
All HIV-positive pregnant women should be started on triple antiretroviral therapy (ART) as early as possible, regardless of CD4 count or viral load, to reduce the risk of vertical transmission. The goal is to achieve an undetectable viral load by the time of delivery. Zidovudine monotherapy is inadequate in the modern era for women with detectable viral loads. With viral load <50 copies/mL near term, vaginal delivery is safe.
Q23 [SBA] (Immunology — Rh) — A 28-year-old RhD-negative primigravida delivers a 3.8 kg RhD-positive baby. The Kleihauer test shows a fetomaternal haemorrhage of 12 mL of fetal blood. Which of the following is the most appropriate dose of anti-D immunoglobulin? A) 250 IU (standard dose) B) 500 IU C) 1500 IU D) 500 IU plus an additional 125 IU per mL of FMH > 6 mL E) 1500 IU plus an additional 125 IU per mL of FMH > 6 mL
Answer: D
In the UK, the standard postnatal anti-D dose is 500 IU, which covers a fetomaternal haemorrhage (FMH) of up to 6 mL of fetal RBCs. For FMH > 6 mL, the recommended regimen is to give 500 IU plus an additional 125 IU per mL of FMH above 6 mL. Since the FMH is 12 mL (6 mL above the threshold), additional dosing is required to ensure adequate coverage and prevent Rh sensitisation.
Q24 [SBA] (Biochemistry — Placental biochemistry) — Which of the following placental enzymes is responsible for converting inactive cortisone to active cortisol in the fetal compartment? A) 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) B) 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2) C) Aromatase (CYP19) D) 17α-hydroxylase E) 3β-hydroxysteroid dehydrogenase
Answer: A
11β-HSD1 is expressed in fetal tissues and converts cortisone (inactive) to cortisol (active). In contrast, 11β-HSD2 in the placenta (trophoblast) converts cortisol to cortisone, protecting the fetus from excess maternal glucocorticoids. This placental barrier is crucial for normal fetal development. Aromatase converts androgens to oestrogens. 3β-HSD is involved in all steroidogenic tissues.
Q25 [SBA] (Genetics — Trinucleotide) — A 35-year-old woman with a family history of Fragile X syndrome undergoes genetic counselling. She is found to have 85 CGG repeats in the FMR1 gene. Which of the following describes her status and associated risks? A) Full mutation — 100% risk of intellectual disability in male offspring B) Premutation — at risk for fragile X-associated primary ovarian insufficiency (FXPOI) C) Normal — no increased risk D) Premutation — at risk for fragile X-associated tremor/ataxia syndrome (FXTAS) in her offspring E) Full mutation — 50% risk of fragile X syndrome in offspring regardless of sex
Answer: B
An FMR1 allele with 55–200 CGG repeats is a premutation (grey zone is 45–54). Women with a premutation are at increased risk for FXPOI (fragile X-associated primary ovarian insufficiency), with approximately 20% developing menopause before age 40. They are also at risk for FXTAS themselves in later life. Offspring of a premutation carrier female are at risk of inheriting an expanded full mutation (>200 repeats) if the expansion occurs during oogenesis.
Q26 [MBA] (Embryology — Gonadal development) — A newborn is found to have ambiguous genitalia with a 46,XY karyotype. Which of the following gene mutations could explain this phenotype? Select ALL that apply. A) SRY mutation B) SOX9 mutation C) NR5A1 (SF-1) mutation D) DAX1 duplication E) FMR1 premutation
Answer: A, B, C, D
46,XY DSD can result from mutations in genes involved in testicular determination and development. SRY (the testis-determining factor) mutations cause complete or partial gonadal dysgenesis. SOX9 downstream of SRY is critical for Sertoli cell differentiation. NR5A1 (SF-1) regulates multiple steroidogenic enzymes. DAX1 duplication causes dosage-sensitive sex reversal by antagonising SRY. FMR1 premutation is not associated with DSD.
Q27 [SBA] (Statistics — Survival) — A Kaplan-Meier survival analysis is performed comparing women with advanced ovarian cancer receiving standard chemotherapy versus standard chemotherapy plus a maintenance PARP inhibitor. The 5-year overall survival in the control group is 40% versus 55% in the experimental group. Which of the following conclusions is correct regarding the interpretation of this survival analysis? A) The median survival has increased by 15 months B) The hazard ratio can be calculated directly from survival proportions at 5 years C) The absolute increase in 5-year survival is 15% D) The PARP inhibitor reduces the relative risk of death by 15% E) Censored data is not included in the Kaplan-Meier calculation
Answer: C
The absolute increase in 5-year survival is 55% − 40% = 15%. The median survival cannot be determined from survival proportions alone (it requires individual patient time-to-event data). Hazard ratios require Cox regression analysis, not simple proportion comparisons. The relative risk reduction would be (55−40)/40 × 100% = 37.5%, not 15%. Kaplan-Meier analysis appropriately accounts for censored data.
Q28 [SBA] (Clinical/Surgical — Electrosurgery) — During a laparoscopic salpingo-oophorectomy, the surgeon uses bipolar diathermy to coagulate the infundibulopelvic ligament before cutting. Which of the following best describes the mechanism of tissue coagulation with bipolar diathermy? A) Current passes from the active electrode through the patient's body to a return electrode (patient plate) B) High-frequency alternating current passes between two electrodes on the forceps, localising current to the grasped tissue C) Direct current causes electrolysis of tissue water D) Low-frequency current causes thermal coagulation by resistive heating E) Ultrasonic vibration generates frictional heat within the tissue
Answer: B
In bipolar diathermy, both the active and return electrodes are incorporated into the instrument (e.g., forceps tips). Current passes only through the tissue grasped between the two electrodes, providing localised coagulation with minimal spread (typically <2 mm). This makes it safer near vital structures. Monopolar diathermy uses a remote return electrode (patient plate) and current passes through the patient's body.
Q29 [SBA] (Anatomy — Abdominal wall) — A 40-year-old woman undergoes a Pfannenstiel incision for caesarean section. Extension of the incision laterally beyond the lateral border of the rectus sheath may injure which of the following neurovascular structures? A) Iliohypogastric nerve B) Ilioinguinal nerve C) Genitofemoral nerve D) Femoral nerve E) Lateral femoral cutaneous nerve
Answer: A
The Pfannenstiel incision extends through the skin, subcutaneous tissue, and rectus sheath. If extended laterally beyond the lateral border of the rectus sheath, the iliohypogastric nerve (L1) — which runs between the internal oblique and transversus abdominis muscles — is at risk of injury. The ilioinguinal nerve runs more inferiorly. Both nerves supply sensory innervation to the suprapubic region and labia.
Q30 [SBA] (Reproductive Physiology — Cervical ripening) — A 38-year-old woman at 41 weeks' gestation undergoes induction of labour with a dinoprostone (PGE2) pessary. Which of the following best describes the physiological role of prostaglandins in cervical ripening? A) Stimulation of uterine smooth muscle contraction alone B) Increased collagen crosslinking and cervical rigidity C) Activation of matrix metalloproteinases causing collagen breakdown and increased hyaluronan D) Inhibition of cyclooxygenase-2 reducing inflammatory mediators E) Direct relaxation of the internal cervical os via beta-adrenergic receptors
Answer: C
Prostaglandins (particularly PGE2) play a crucial role in cervical ripening by activating matrix metalloproteinases (MMPs) that degrade collagen fibres in the cervical stroma. They also increase hyaluronan and water content, making the cervix softer and more compliant. This occurs before the onset of regular uterine contractions. Prostaglandins also promote gap junction formation between myometrial cells.
Q31 [MBA] (Endocrinology — Menopause) — A 52-year-old woman presents with vasomotor symptoms and wishes to discuss hormone replacement therapy (HRT). She has a uterus and no contraindications. Which of the following are correct statements regarding HRT? Select ALL that apply. A) Oestrogen alone should be prescribed in women with a uterus B) Continuous combined HRT is appropriate if she is >1 year postmenopausal C) The risk of venous thromboembolism is lower with transdermal compared to oral oestrogen D) Tibolone is contraindicated in women with a history of breast cancer E) Oestrogen therapy increases the risk of colorectal cancer
Answer: B, C, D
Women with a uterus require a progestogen (cyclical or continuous combined) to prevent endometrial hyperplasia/carcinoma caused by unopposed oestrogen (contra A). Continuous combined HRT is appropriate for postmenopausal women >1 year from last menstrual period. Transdermal oestrogen has a lower VTE risk compared to oral oestrogen as it avoids first-pass hepatic metabolism. Tibolone increases recurrence risk in breast cancer survivors. HRT reduces colorectal cancer risk (contra E).
Q32 [SBA] (Fetal/Neonatal Physiology — Cord gases) — A term neonate is delivered with poor respiratory effort and low Apgar scores. Umbilical cord blood gas analysis shows: pH 7.10, pCO2 65 mmHg, pO2 25 mmHg, base excess −12 mmol/L. Which of the following best describes this acid-base picture? A) Metabolic acidosis alone B) Respiratory acidosis alone C) Mixed respiratory and metabolic acidosis D) Compensated metabolic acidosis E) Normal cord gas parameters
Answer: C
The cord gas shows acidaemia (pH < 7.15) with both elevated pCO2 (respiratory component, normal ~40-50 mmHg) and significant base deficit (metabolic component, normal > −8 mmol/L). This mixed acidosis is common in acute intrapartum hypoxia followed by anaerobic metabolism. The respiratory component reflects impaired gas exchange, while the metabolic component reflects lactic acidosis from anaerobic glycolysis.
Q33 [SBA] (Pathology — Endometrial pathology) — A 60-year-old woman presents with postmenopausal bleeding. Endometrial biopsy shows complex atypical hyperplasia. She is not a surgical candidate due to severe cardiac comorbidities. Which of the following is the most appropriate medical management? A) Oral medroxyprogesterone acetate B) Levonorgestrel intrauterine system (LNG-IUS) C) Tamoxifen D) GnRH agonist E) Aromatase inhibitor
Answer: B
The LNG-IUS (Mirena) is the most effective medical therapy for complex atypical hyperplasia, achieving regression rates of 80-90%. It delivers high-dose progestogen directly to the endometrium with minimal systemic side effects. Oral progestogens are less effective due to variable absorption and systemic side effects. Tamoxifen is oestrogenic on the endometrium and would worsen the condition.
Q34 [SBA] (Pharmacology — GnRH analogues) — A 30-year-old woman with symptomatic uterine fibroids is being treated with a GnRH agonist (leuprolide) before planned myomectomy. After 8 weeks of treatment, she reports significant hot flushes and reduced fibroid size on ultrasound. Which of the following best explains the mechanism of action of GnRH agonists in this context? A) Competitive antagonism at the GnRH receptor B) Initial gonadotrophin surge followed by receptor downregulation and pituitary desensitisation C) Direct inhibition of oestrogen synthesis in the ovary D) Selective oestrogen receptor modulation in uterine tissue E) Inhibition of aromatase in fibroid tissue
Answer: B
GnRH agonists initially cause an increase in LH and FSH secretion (flare effect) lasting 1-2 weeks, followed by downregulation and desensitisation of pituitary GnRH receptors, leading to profound hypogonadotrophic hypogonadism. This oestrogen-deficient state causes fibroid shrinkage but also menopausal symptoms (hot flushes, bone loss). GnRH antagonists (e.g., relugolix) cause immediate suppression without a flare.
Q35 [SBA] (Microbiology — Congenital infections) — A newborn presents with petechiae, hepatosplenomegaly, microcephaly, and intracranial calcifications detected on cranial ultrasound. Maternal history is unremarkable. Which of the following is the most likely causative organism? A) Toxoplasma gondii B) Rubella virus C) Cytomegalovirus D) Herpes simplex virus E) Parvovirus B19
Answer: C
Cytomegalovirus (CMV) is the most common congenital infection worldwide and classically presents with petechiae (due to thrombocytopenia), hepatosplenomegaly, microcephaly, and periventricular intracranial calcifications. Rubella causes cataracts, cardiac defects, and sensorineural deafness — the triad of congenital rubella syndrome. Toxoplasma causes hydrocephalus, not microcephaly, and calcifications are typically diffuse.
Q36 [MBA] (Immunology — Pregnancy immunology) — Which of the following immune adaptations occur in normal pregnancy to maintain fetal tolerance? Select ALL that apply. A) Shift from Th1 to Th2 predominant immune response B) Increased regulatory T cell (Treg) activity C) Reduced NK cell activity at the decidua D) Upregulation of HLA-G on trophoblast cells E) Increased complement activation at the maternal-fetal interface
Answer: A, B, D
Normal pregnancy involves a shift from Th1 (cell-mediated) to Th2 (humoral) predominant immunity, protecting the fetus from cytotoxic immune attack. Treg cells expand and suppress alloreactive immune responses. HLA-G (a non-classical MHC class I molecule) is expressed on extravillous trophoblast and inhibits NK cell killing. Decidual NK cells (CD56bright) are abundant but have a unique phenotype focused on spiral artery remodelling, not cytotoxicity.
Q37 [SBA] (Biochemistry — Enzymes in O&G) — A 30-year-old woman with polycystic ovary syndrome (PCOS) undergoes a 75 g oral glucose tolerance test. Fasting glucose is 5.8 mmol/L and 2-hour glucose is 9.2 mmol/L. Which of the following enzymes is most likely impaired in its insulin-stimulated action in this condition? A) Hexokinase B) Glycogen synthase C) Lipoprotein lipase D) Glucose-6-phosphatase E) Phosphofructokinase-1
Answer: B
Insulin resistance in PCOS and gestational diabetes is characterised by impaired insulin-stimulated glycogen synthesis in skeletal muscle. Glycogen synthase is the key enzyme that converts glucose to glycogen in response to insulin. This is the primary pathway of glucose disposal after a meal. Hexokinase and phosphofructokinase-1 are involved in glycolysis. Glucose-6-phosphatase is involved in gluconeogenesis.
Q38 [SBA] (Genetics — Mitochondrial) — A 30-year-old woman is known to carry a heteroplasmic mitochondrial DNA mutation at a low level in her blood. She has no symptoms. She wishes to understand the risk of transmission to her children. Which of the following counselling points is correct? A) All children will inherit the mutation because mitochondrial DNA is maternally inherited B) Only daughters will inherit the mutation C) The mutation load in offspring may vary due to the mitochondrial bottleneck during oogenesis D) The risk of transmission depends on the father's mitochondrial DNA status E) Mitochondrial DNA mutations follow Mendelian inheritance patterns
Answer: C
Mitochondrial DNA is maternally inherited, but the proportion of mutated mtDNA (heteroplasmy) in offspring can vary unpredictably due to the genetic bottleneck — a reduction in mtDNA copy number during oogenesis followed by random amplification. This means a mother with low-level heteroplasmy in blood could have children with higher or lower mutation loads. The father's mtDNA is not transmitted. Inheritance is not Mendelian.
Q39 [SBA] (Embryology — DSD) — A newborn is noted to have ambiguous genitalia with a phallic structure, labioscrotal folds, and a single perineal opening. Karyotype is 46,XX. Ultrasound reveals a uterus and ovaries. Which of the following is the most likely diagnosis? A) Complete androgen insensitivity syndrome B) Congenital adrenal hyperplasia (21-hydroxylase deficiency) C) 5α-reductase deficiency D) Ovotesticular DSD E) Turner syndrome
Answer: B
46,XX DSD with ambiguous genitalia is most commonly caused by congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency. This results in cortisol deficiency and shunting of precursors into androgen biosynthesis, causing in utero virilisation of a female fetus. The presence of a uterus and ovaries confirms female internal genitalia. Complete androgen insensitivity syndrome (46,XY) presents with female external genitalia.
Q40 [SBA] (Statistics — Bias) — A retrospective cohort study investigates the association between maternal obesity and caesarean section rate. The researchers find that obese women are more likely to have labour induction, which itself is associated with caesarean section. When adjusting for induction of labour, the association between obesity and caesarean section weakens. Which type of bias or confounding is demonstrated? A) Selection bias B) Recall bias C) Confounding by indication D) Detection bias E) Lead-time bias
Answer: C
Confounding by indication occurs when the indication for an intervention (here, induction of labour) is associated with both the exposure (obesity) and the outcome (caesarean section). Obese women are more likely to be induced, and induction is associated with higher caesarean rates. This creates a confounding pathway that can be addressed by multivariable regression or stratification.
Q41 [SBA] (Clinical/Surgical — Consent) — A 36-year-old woman with a 10-cm symptomatic ovarian cyst is scheduled for a right oophorectomy under general anaesthesia. She has signed a consent form for a right oophorectomy. During surgery, the left ovary also appears abnormal with a suspicious 3-cm cyst. Which of the following best describes the legal position regarding extending the surgery? A) The surgeon may proceed if it is in the patient's best interests B) The surgeon may proceed only if it is a life-threatening emergency and consent cannot be obtained C) The surgeon may proceed with verbal consent from a relative D) The surgeon must close and obtain separate consent for a second procedure E) The surgeon may proceed as the patient signed a general surgical consent
Answer: B
In UK law (Montgomery principles and GMC guidance), a surgeon may only extend an operation beyond the consented procedure without specific consent when it is an emergency where delay would threaten life or cause significant harm, and the patient is unable to consent. An abnormal but non-emergent finding on the contralateral ovary does not meet this threshold. The appropriate action is to close, inform the patient, and schedule a second procedure after proper counselling.
Q42 [SBA] (Anatomy — Perineum) — A 34-year-old woman undergoes an episiotomy during operative vaginal delivery. Which of the following muscles is most directly affected by a right mediolateral episiotomy? A) Bulbospongiosus B) Ischiocavernosus C) Superficial transverse perineal muscle D) Deep transverse perineal muscle E) Pubococcygeus
Answer: C
A mediolateral episiotomy extends from the posterior fourchette at an angle of approximately 60° from the midline. This incision passes through the vaginal mucosa, perineal skin, and the superficial transverse perineal muscle. The bulbospongiosus (surrounds the vaginal introitus) may also be partially involved. The ischiocavernosus is lateral and not typically affected.
Q43 [SBA] (Reproductive Physiology — Parturition) — Which of the following correctly describes the role of fetal cortisol in the initiation of parturition? A) It directly stimulates oxytocin release from the maternal posterior pituitary B) It increases placental oestrogen synthesis by upregulating 17α-hydroxylase/17,20-lyase (CYP17) activity C) It suppresses prostaglandin synthesis by fetal membranes D) It promotes progesterone production by the placenta E) It causes cervical ripening independent of prostaglandins
Answer: B
Rising fetal cortisol near term upregulates placental CYP17 (17α-hydroxylase/17,20-lyase) activity, which converts pregnenolone to DHEAS. This increases oestrogen precursors, shifting the oestrogen:progesterone ratio favouring oestrogen dominance. Oestrogen stimulates gap junction formation, oxytocin receptor expression, and prostaglandin synthesis — all promoting uterine contractility.
Q44 [SBA] (Endocrinology — Prolactin) — A 28-year-old woman presents with galactorrhoea and oligomenorrhoea. Serum prolactin is 1800 mU/L (normal < 500). MRI pituitary shows an 8-mm microadenoma. She wishes to conceive. Which of the following is the most appropriate first-line treatment? A) Trans-sphenoidal adenomectomy B) Cabergoline 0.5 mg twice weekly C) Bromocriptine 2.5 mg twice daily D) Radiotherapy to the pituitary E) Observation with 6-monthly MRI
Answer: B
Cabergoline is the first-line medical treatment for hyperprolactinaemia due to prolactinoma. It is a dopamine D2 receptor agonist that suppresses prolactin secretion and shrinks adenomas. Cabergoline is preferred over bromocriptine due to its longer half-life, better tolerability (less nausea), and higher efficacy. For microprolactinomas, dopamine agonists restore ovulation in 80-90% of patients.
Q45 [MBA] (Fetal/Neonatal Physiology — Thermoregulation) — A preterm neonate born at 26 weeks' gestation is at high risk of hypothermia in the delivery room. Which of the following mechanisms contribute to heat loss in the immediate newborn period? Select ALL that apply. A) Evaporation of amniotic fluid from the skin B) Convection from air currents C) Radiation to colder surrounding surfaces D) Conduction through contact with cold resuscitation equipment E) Non-shivering thermogenesis via brown adipose tissue
Answer: A, B, C, D
Newborns lose heat through four physical mechanisms: evaporation (fluid on skin), convection (air currents), radiation (to cooler surfaces), and conduction (direct contact with cold surfaces). Non-shivering thermogenesis (E) is the mechanism by which newborns generate heat (via brown fat metabolism), not a mechanism of heat loss. Preterm infants are particularly vulnerable due to high surface area-to-volume ratio and immature skin barrier.
Q46 [SBA] (Pathology — GTD) — A 28-year-old woman presents with vaginal bleeding at 10 weeks' gestation. Ultrasound shows a "snowstorm" appearance with no identifiable fetus. Serum hCG is 450,000 IU/L. Suction evacuation is performed and histology shows hydropic chorionic villi with diffuse trophoblastic hyperplasia and no fetal tissue. Which of the following is the most likely diagnosis? A) Invasive mole B) Complete hydatidiform mole C) Partial hydatidiform mole D) Choriocarcinoma E) Placental site trophoblastic tumour
Answer: B
A complete hydatidiform mole (CHM) is characterised by hydropic swelling of all chorionic villi, diffuse trophoblastic hyperplasia, and absence of fetal tissue. The karyotype is typically 46,XX (all paternal). Partial moles show focal hydrops, mild hyperplasia, and may have fetal tissue. Invasive moles show myometrial invasion. Choriocarcinoma lacks villi entirely. Post-evacuation hCG monitoring is essential as 15-20% develop persistent GTD.
Q47 [SBA] (Pharmacology — Immunosuppressants) — A 32-year-old woman with a renal transplant presents at 10 weeks' gestation. She is maintained on tacrolimus, mycophenolate mofetil, and prednisolone. Which of the following drugs should be avoided due to teratogenicity? A) Tacrolimus B) Mycophenolate mofetil C) Prednisolone D) Azathioprine E) Hydroxychloroquine
Answer: B
Mycophenolate mofetil (MMF) is teratogenic and is contraindicated in pregnancy. It is associated with a characteristic embryopathy including cleft lip/palate, microtia, and cardiac defects. Women of childbearing age on MMF should use effective contraception and be switched to alternative immunosuppression (e.g., azathioprine or ciclosporin) before pregnancy. Tacrolimus, prednisolone, and azathioprine are considered relatively safer options in pregnancy.
Q48 [SBA] (Microbiology — Maternal sepsis) — A 30-year-old woman at 38 weeks' gestation presents with fever (39.2°C), uterine tenderness, foul-smelling amniotic fluid, and maternal tachycardia. A diagnosis of chorioamnionitis is made. Which of the following is the most common causative organism? A) Escherichia coli B) Group B Streptococcus C) Ureaplasma urealyticum D) Bacteroides fragilis E) Listeria monocytogenes
Answer: C
Ureaplasma urealyticum and Mycoplasma hominis are the most common organisms isolated in chorioamnionitis, though mixed infections with anaerobes and aerobes are typical. Group B Streptococcus is a common cause of early-onset neonatal sepsis but less frequent in chorioamnionitis. E. coli and Bacteroides are also implicated but Ureaplasma is the single most frequently identified organism in histologic chorioamnionitis.
Q49 [SBA] (Immunology — Autoimmunity) — A 28-year-old woman with systemic lupus erythematosus (SLE) is planning pregnancy. She has a history of lupus nephritis and positive anti-Ro/SSA antibodies. Which of the following is the major fetal risk associated with anti-Ro/SSA antibodies? A) Fetal growth restriction B) Congenital heart block C) Neonatal lupus rash D) Preterm birth E) Hydrops fetalis
Answer: B
Anti-Ro/SSA antibodies can cross the placenta and bind to fetal cardiac conduction tissue, causing congenital heart block (CHB), typically presenting as atrioventricular block detected between 18-24 weeks. The risk is approximately 2% in women with anti-Ro antibodies, rising to ~20% if a previous child was affected. Serial fetal echocardiography is recommended from 16 weeks. Neonatal lupus rash (C) also occurs but is transient and not the major risk.
Q50 [SBA] (Biochemistry — Tumour markers) — A 45-year-old woman presents with abdominal distension. CT shows a large pelvic mass with solid and cystic components. Serum hCG is 120 IU/L, AFP is 350 ng/mL, and LDH is 800 U/L. Which of the following is the most likely diagnosis? A) Mature cystic teratoma B) Dysgerminoma C) Yolk sac tumour D) Mixed germ cell tumour E) Serous cystadenocarcinoma
Answer: D
The presence of elevated hCG, AFP, and LDH suggests a mixed germ cell tumour, as different markers are produced by different germ cell components. hCG indicates choriocarcinoma or syncytiotrophoblast elements, AFP indicates yolk sac elements, and LDH is elevated in dysgerminoma. A pure dysgerminoma would only elevate LDH. A pure yolk sac tumour would only elevate AFP. Mature teratomas are benign and do not elevate markers.
Q51 [SBA] (Genetics — Pharmacogenetics) — A 38-year-old woman with breast cancer is found to carry a BRCA1 mutation and is being considered for PARP inhibitor therapy (olaparib). Which of the following best describes the pharmacogenetic rationale for using PARP inhibitors in BRCA-mutated cancers? A) PARP inhibitors activate BRCA1 gene expression B) Synthetic lethality — loss of both PARP and BRCA-mediated DNA repair leads to cell death C) PARP inhibitors directly repair BRCA1 mutations D) BRCA1 mutations make cancer cells resistant to chemotherapy, requiring alternative agents E) PARP inhibitors reduce oestrogen synthesis in BRCA-mutated cells
Answer: B
PARP inhibitors exploit the concept of synthetic lethality. BRCA1/2 mutations impair homologous recombination repair (HRR) of double-strand DNA breaks. PARP inhibitors block single-strand break repair, leading to the accumulation of double-strand breaks during replication that cannot be repaired by HRR-deficient cells, resulting in selective cancer cell death. Normal cells with at least one functional BRCA allele can still repair damage.
Q52 [MBA] (Embryology — Congenital anomalies) — Which of the following are associated with failure of the cloaca to divide correctly during embryological development? Select ALL that apply. A) Persistent cloaca B) Rectovaginal fistula C) Imperforate anus D) Hypospadias E) Urethral duplication
Answer: A, B, C
The cloaca divides into the urogenital sinus (anteriorly) and the anorectal canal (posteriorly) following descent of the urorectal septum during weeks 4-7. Failure of complete division results in persistent cloaca (common channel), rectovaginal fistula, or imperforate anus depending on the severity and timing. Hypospadias results from failure of urethral fold fusion. Urethral duplication is a rare anomaly from abnormal urethral plate development.
Q53 [SBA] (Statistics — Screening) — A screening test for pre-eclampsia using placental growth factor (PlGF) has a sensitivity of 85% and a specificity of 92%. The prevalence of pre-eclampsia in the population being tested is 3%. Which of the following is the positive predictive value (PPV) closest to? A) 15% B) 25% C) 50% D) 75% E) 85%
Answer: B
Using a 2×2 table approach with 10,000 women: pre-eclampsia prevalence = 3% (300 cases). True positives = 300 × 0.85 = 255. False positives = 9700 × 0.08 = 776. PPV = TP / (TP + FP) = 255 / (255 + 776) = 255 / 1031 ≈ 24.7%. This illustrates that even with good sensitivity/specificity, PPV is low when disease prevalence is low.
Q54 [SBA] (Clinical/Surgical — Guidelines) — A 26-year-old woman presents to the emergency department with heavy vaginal bleeding at 9 weeks' gestation. She has hypotension (90/50 mmHg) and tachycardia (110/min). Transvaginal ultrasound shows an empty uterine cavity with a thickened endometrium and an adnexal mass. Serum hCG is 8500 IU/L. She has RhD-negative blood type. Which of the following is the most appropriate immediate management step? A) Transvaginal ultrasound to identify fetal pole B) Diagnostic laparoscopy C) Intravenous fluid resuscitation and emergency laparotomy D) Administer anti-D immunoglobulin before surgical intervention E) Measure serum progesterone level
Answer: D
In a haemodynamically unstable woman with suspected ectopic pregnancy and RhD-negative blood type, anti-D immunoglobulin should be administered urgently before any surgical intervention. The NICE and RCOG guidelines recommend anti-D prophylaxis for all RhD-negative women undergoing surgical evacuation or experiencing bleeding in early pregnancy. IV fluids and surgery are also needed, but the anti-D question is the specific guideline-related priority.
Q55 [SBA] (Anatomy — Surgical anatomy) — During a laparoscopic sacrocolpopexy, the surgeon must identify the sacral promontory to attach the mesh. Which of the following anatomical relationships is most useful in identifying this landmark? A) Bifurcation of the abdominal aorta at L4 B) The right ureter crossing the common iliac artery bifurcation C) The median sacral artery running over the sacral promontory D) The sigmoid colon attaching to the left pelvic brim E) The psoas muscle running along the lateral pelvic sidewall
Answer: B
The right ureter crossing the right common iliac artery bifurcation is the most reliable landmark for identifying the sacral promontory laparoscopically. The ureter can be seen crossing the iliac vessels, and the sacral promontory lies immediately medial and posterior to this point. The aortic bifurcation at L4 is approximately at the level of the umbilicus, not the promontory. The median sacral artery is small and variable.
Q56 [SBA] (Reproductive Physiology — Cervical ripening) — Which of the following biochemical changes is most characteristic of the ripe cervix at term? A) Increased collagen content with decreased water content B) Decreased hyaluronan and increased dermatan sulphate C) Increased collagen solubility and increased matrix metalloproteinase activity D) Increased cervical rigidity with smooth muscle contraction E) Increased elastin fibres with decreased proteoglycans
Answer: C
Cervical ripening involves degradation and remodelling of the collagen network. Collagen solubility increases as MMPs (particularly MMP-8 and MMP-9) break down collagen crosslinks. There is also an increase in hyaluronan (which attracts water), decreased collagen content, and increased glycosaminoglycan turnover. These changes result in a softer, more compliant cervix that is capable of dilating during labour.
Q57 [SBA] (Endocrinology — AMH) — A 38-year-old woman undergoes fertility assessment. Day 3 FSH is 12 IU/L and anti-Müllerian hormone (AMH) is 4 pmol/L (normal > 10). Which of the following best describes the origin and physiological role of AMH? A) Produced by theca cells, promotes follicular recruitment B) Produced by granulosa cells of pre-antral and small antral follicles, inhibits primordial follicle recruitment C) Produced by the anterior pituitary, stimulates antral follicle growth D) Produced by the corpus luteum, supports luteal phase E) Produced by the oocyte, regulates meiotic arrest
Answer: B
AMH is produced by granulosa cells of pre-antral and small antral follicles (up to 6-8 mm). Its primary role is to inhibit the recruitment of primordial follicles into the growing pool, thereby regulating the rate of follicular depletion. Serum AMH levels correlate with the ovarian reserve (number of antral follicles) and decline with age. Low AMH (as in this patient) suggests diminished ovarian reserve.
Q58 [MBA] (Fetal/Neonatal Physiology — Respiratory) — A 34-week preterm neonate develops respiratory distress syndrome and requires intubation and surfactant therapy. Which of the following are beneficial effects of exogenous surfactant administration? Select ALL that apply. A) Reduced alveolar surface tension B) Improved lung compliance C) Decreased functional residual capacity D) Reduced need for high ventilatory pressures E) Reduced risk of bronchopulmonary dysplasia
Answer: A, B, D, E
Exogenous surfactant reduces alveolar surface tension (A), preventing alveolar collapse at end-expiration. This improves lung compliance (B), allowing ventilation at lower pressures (D), which reduces barotrauma and the risk of bronchopulmonary dysplasia (E). Functional residual capacity (C) is increased, not decreased, as surfactant stabilises alveoli and prevents collapse.
Q59 [SBA] (Pathology — Ovarian tumours) — A 22-year-old woman presents with acute lower abdominal pain and an adnexal mass. Ultrasound shows a 7-cm unilocular ovarian cyst with thin walls and no solid components. Tumour markers are normal. She undergoes ovarian cystectomy. Histology shows a cyst lined by stratified squamous epithelium with keratin debris and hair shafts in the lumen. Which of the following is the most likely diagnosis? A) Serous cystadenoma B) Mucinous cystadenoma C) Mature cystic teratoma D) Cystic granulosa cell tumour E) Endometrioma
Answer: C
Mature cystic teratoma (dermoid cyst) is the most common ovarian germ cell tumour in women of reproductive age. It is composed of well-differentiated tissues derived from all three germ layers. The presence of stratified squamous epithelium, keratin, and hair is characteristic. They are benign in >99% of cases. Serous cystadenomas are lined by tubal-type epithelium. Endometriomas contain chocolate-coloured fluid with endometrial-type stroma.
Q60 [SBA] (Pharmacology — Contraceptives) — A 19-year-old nulliparous woman requests the copper intrauterine device (Cu-IUD) for contraception. She has no medical comorbidities and is not on any medications. Her last menstrual period was 3 weeks ago and she had unprotected intercourse yesterday. Which of the following is correct regarding emergency contraception with the Cu-IUD? A) It is ineffective if inserted more than 72 hours after unprotected intercourse B) It can be inserted up to 5 days after unprotected intercourse C) It must be inserted within 24 hours to prevent pregnancy D) It is contraindicated in nulliparous women E) It is less effective than oral emergency contraception
Answer: B
The copper IUD is the most effective form of emergency contraception (99% efficacy) and can be inserted up to 5 days after unprotected intercourse. It works by causing a sterile inflammatory response that is toxic to sperm and prevents implantation. It can be used in nulliparous women without contraindication. It is more effective than oral emergency contraception (ulipristal acetate or levonorgestrel). After insertion, it provides ongoing contraception for up to 10 years.
Q61 [SBA] (Microbiology — Congenital infections) — A pregnant woman at 16 weeks' gestation develops a febrile illness with arthralgia and a maculopapular rash. Her 5-year-old son recently had a similar illness. Serology shows: Parvovirus B19 IgM positive, IgG negative. Which of the following is the greatest risk to the fetus? A) Congenital cataracts B) Hydrops fetalis due to severe anaemia C) Sensorineural deafness D) Intracranial calcifications E) Cardiac defects
Answer: B
Parvovirus B19 infects erythroid progenitor cells via the P antigen (globoside) receptor, causing aplastic crisis. In pregnancy, this can lead to fetal anaemia, high-output cardiac failure, and hydrops fetalis. The risk is highest when maternal infection occurs before 20 weeks (11% risk of fetal loss/hydrops). Cataracts are associated with rubella. Deafness and calcifications are associated with CMV. The P antigen is also expressed on cardiac cells but hydrops is the classic fetal manifestation.
Q62 [SBA] (Immunology — Pregnancy immunology) — A 32-year-old woman presents with recurrent miscarriages at 10-12 weeks' gestation. She is found to have a positive lupus anticoagulant. Which of the following best describes the mechanism by which antiphospholipid antibodies cause pregnancy loss? A) Direct antibody-mediated attack on fetal tissues B) Activation of complement pathways leading to placental inflammation and thrombosis C) Inhibition of trophoblast invasion into the decidua D) Induction of maternal antibody production against fetal HLA E) Blockade of progesterone receptors on the endometrium
Answer: C
Antiphospholipid antibodies (aPL) primarily cause pregnancy loss by inhibiting trophoblast function and invasion. aPL bind to β2-glycoprotein I expressed on trophoblast cells, interfering with intercellular fusion, hCG production, and invasion into the decidua. This leads to defective placentation. Complement activation and thrombosis contribute later but the primary pathogenic mechanism is impaired trophoblast invasion. Treatment with low-dose aspirin and heparin improves outcomes.
Q63 [SBA] (Biochemistry — Placental biochemistry) — A 40-year-old woman with a BMI of 38 kg/m² undergoes a glucose tolerance test at 28 weeks' gestation. Her fasting glucose is 6.4 mmol/L. Which of the following placental hormones is most directly responsible for the physiological insulin resistance of pregnancy? A) Oestradiol B) Progesterone C) Human placental lactogen (hPL) D) Human chorionic gonadotrophin (hCG) E) Corticotrophin-releasing hormone (CRH)
Answer: C
Human placental lactogen (hPL), also called human chorionic somatomammotropin, is the primary hormone driving insulin resistance in pregnancy. It is structurally similar to growth hormone, increases lipolysis, and reduces maternal glucose utilisation, thereby ensuring glucose availability for the fetus. Together with placental growth hormone and cortisol, hPL creates a diabetogenic state. Progesterone and oestradiol contribute but hPL is the most potent. This physiological insulin resistance can unmask GDM.
Q64 [SBA] (Genetics — BRCA) — A 45-year-old woman with high-grade serous ovarian carcinoma undergoes genetic testing and is found to have a BRCA1 mutation. Which of the following best describes the role of BRCA1 in normal cell function? A) Cell cycle checkpoint regulation at G1/S phase B) Double-strand DNA break repair via homologous recombination C) Mismatch repair of single nucleotide errors D) Nucleotide excision repair of bulky DNA adducts E) Base excision repair of oxidative damage
Answer: B
BRCA1 and BRCA2 are tumour suppressor genes that encode proteins essential for homologous recombination repair (HRR) of double-strand DNA breaks. When BRCA1 is mutated, cells cannot accurately repair these breaks, leading to genomic instability and cancer predisposition. This defect is also the basis for synthetic lethality with PARP inhibitors. Mismatch repair is the domain of MLH1, MSH2, etc. (Lynch syndrome). Base excision repair involves different proteins.
Q65 [SBA] (Embryology — Congenital anomalies) — A newborn female presents with a smooth, red-purple, soft mass protruding from the vaginal introitus. A diagnosis of hydrometrocolpos is suspected. Which of the following embryological abnormalities most likely underlies this condition? A) Failure of the urogenital sinus to form B) Imperforate hymen with accumulation of secretions C) Absent paramesonephric (Müllerian) ducts D) Failure of the mesonephric ducts to regress E) Vaginal agenesis (Mayer-Rokitansky-Küster-Hauser syndrome)
Answer: B
Hydrometrocolpos in the newborn results from an imperforate hymen causing accumulation of maternal oestrogen-stimulated cervical and vaginal secretions behind the obstruction. The imperforate hymen represents persistence of the urogenital membrane that normally ruptures during fetal development. In adolescents, this presents as haematocolpos/ haematometra with cyclical pain. Vaginal agenesis (MRKH) presents with primary amenorrhoea, not an obstructive mass.
Q66 [MBA] (Statistics — Likelihood ratios) — A 40-year-old woman with a family history of ovarian cancer has a CA-125 level of 85 U/mL. The test has a sensitivity of 79% and a specificity of 78% for detecting ovarian cancer in symptomatic women. Which of the following statements about likelihood ratios are correct? Select ALL that apply. A) The positive likelihood ratio (LR+) is approximately 3.6 B) The negative likelihood ratio (LR−) is approximately 0.27 C) A likelihood ratio > 10 is required to rule in a diagnosis D) Likelihood ratios are independent of disease prevalence E) The post-test probability can be calculated using the pre-test probability and likelihood ratio
Answer: A, B, D, E
LR+ = sensitivity / (1 − specificity) = 0.79 / 0.22 ≈ 3.59. LR− = (1 − sensitivity) / specificity = 0.21 / 0.78 ≈ 0.27. Likelihood ratios are independent of prevalence (unlike PPV/NPV). Post-test probability can be determined using the Fagan nomogram or by converting probability to odds. While LR+ > 10 provides strong diagnostic evidence, an LR+ of 3.6 still increases the probability of disease moderately.
Q67 [SBA] (Clinical/Surgical — Instruments) — A surgeon is performing a laparoscopic salpingectomy for an ectopic pregnancy. The tube is bleeding and the surgeon needs to achieve haemostasis. Which of the following instruments delivers bipolar energy and also has a cutting mechanism, making it ideal for this procedure? A) Ligasure™ B) Maryland dissector (bipolar) C) Endoscopic loop ligature (Endoloop) D) Laparoscopic stapler (Endo GIA) E) Monopolar hook electrode
Answer: A
Ligasure™ is a bipolar vessel sealing device that uses impedance-based feedback to deliver precisely controlled energy, fusing collagen and elastin in vessel walls to achieve permanent haemostasis. It includes a cutting mechanism, making it ideal for laparoscopic salpingectomy where the mesosalpinx needs to be both sealed and divided. Maryland bipolar dissectors coagulate but lack a cutting function. Endo GIA staplers are bulky for a slender tube.
Q68 [MBA] (Anatomy — Surgical anatomy) — A 52-year-old woman undergoes a radical hysterectomy (Wertheim's procedure) for FIGO stage IB cervical cancer. Which of the following anatomical structures are routinely removed or dissected as part of this procedure? Select ALL that apply. A) Uterus and cervix B) Ovaries and fallopian tubes C) Parametrial tissue (paracervical and paravaginal) D) Pelvic lymph nodes E) Upper two-thirds of the vagina
Answer: A, C, D, E
Wertheim's radical hysterectomy (Type III) involves en bloc removal of the uterus, cervix, parametrial tissue (including paracervical and paravaginal tissue), upper third to half of the vagina, and pelvic lymphadenectomy. Oophorectomy (B) may be performed depending on the patient's age and ovarian status but is not a mandatory component of the radical hysterectomy for cervical cancer.
Q69 [SBA] (Reproductive Physiology — Lactation) — A 33-year-old breastfeeding woman develops mastitis with fever and breast erythema. She is treated with antibiotics and advised to continue breastfeeding. Which of the following correctly describes the composition of human breast milk? A) Colostrum has lower protein and higher fat content than mature milk B) The predominant whey protein in breast milk is casein C) Breast milk contains secretory IgA, lactoferrin, and lysozyme that provide passive immunity D) The fat content of breast milk is constant throughout a feed E) Human milk oligosaccharides are primarily a nutritional carbohydrate source for the infant
Answer: C
Breast milk contains multiple bioactive components that provide passive immunity, including secretory IgA (which coats the infant's gut mucosa), lactoferrin (bacteriostatic iron-binding protein), and lysozyme (antibacterial enzyme). Colostrum has higher protein and lower fat than mature milk. The predominant whey protein is α-lactalbumin, not casein. Fat content increases during a feed (hindmilk has higher fat). Human milk oligosaccharides are prebiotics, not nutritional carbohydrates.
Q70 [SBA] (Endocrinology — Adrenal) — A 28-year-old woman presents with fatigue, hyperpigmentation of the knuckles and gingiva, postural hypotension, and hyponatraemia. Short Synacthen test shows a baseline cortisol of 80 nmol/L and a 30-minute cortisol of 120 nmol/L (normal > 550). ACTH is 500 pg/mL (normal 10-50). Which of the following is the most likely diagnosis? A) Primary adrenal insufficiency (Addison's disease) B) Secondary adrenal insufficiency (pituitary failure) C) Tertiary adrenal insufficiency (hypothalamic failure) D) Congenital adrenal hyperplasia E) Cushing's disease
Answer: A
The clinical features of hyperpigmentation (due to high ACTH stimulating melanocytes), postural hypotension, hyponatraemia, and a flat Synacthen response (cortisol fails to rise above 550 nmol/L) with high ACTH indicate primary adrenal failure. In primary adrenal insufficiency, the adrenal gland fails to produce cortisol despite elevated ACTH. Secondary and tertiary causes show low or inappropriately normal ACTH. Hyperpigmentation is a key distinguishing feature of primary disease.
Q71 [SBA] (Fetal/Neonatal Physiology — Jaundice) — A term neonate born at 39 weeks by vacuum extraction has a large cephalhaematoma. On day 3, the bilirubin is 320 µmol/L. The baby is otherwise well, feeding adequately, and has no signs of haemolysis. Which of the following is the most likely contributor to the jaundice? A) Breast milk jaundice B) Physiological jaundice due to immature UDP-glucuronosyltransferase activity C) Extravascular haemolysis from the cephalhaematoma D) Biliary atresia E) ABO incompatibility
Answer: C
A cephalhaematoma is a subperiosteal collection of blood that can be reabsorbed into the circulation, providing a large haemoglobin load that exceeds the neonatal liver's capacity to conjugate bilirubin. This causes an exaggerated unconjugated hyperbilirubinaemia. Physiological jaundice typically peaks at day 3-5 at lower levels. Breast milk jaundice occurs later (day 5-14). Biliary atresia causes conjugated hyperbilirubinaemia. ABO incompatibility would show signs of haemolysis.
Q72 [SBA] (Pathology — GTD) — A 32-year-old woman is being monitored following evacuation of a complete hydatidiform mole. At 12 weeks post-evacuation, her hCG level has plateaued at 150 IU/L. She has not used contraception and has a negative urine pregnancy test 4 weeks ago. Which of the following is the most likely diagnosis? A) Normal post-molar hCG regression B) Persistent gestational trophoblastic disease (GTD) C) Recurrent molar pregnancy D) Choriocarcinoma E) New intrauterine pregnancy
Answer: B
Persistent GTD is defined by a plateau in hCG for 4 consecutive measurements over 3 weeks or a re-elevation after a negative result. This patient's hCG plateauing at 150 IU/L at 12 weeks meets the criteria. She requires staging and likely chemotherapy (methotrexate or actinomycin D). A new pregnancy would show rising hCG. Recurrent molar pregnancy is rare (<1%). Choriocarcinoma is a histological diagnosis, not a clinical one.
Q73 [SBA] (Pharmacology — Chemotherapy) — A 52-year-old woman with advanced ovarian cancer is being treated with cisplatin-based chemotherapy. She develops tinnitus and high-frequency hearing loss during treatment. Which of the following best describes the mechanism of cisplatin ototoxicity? A) Inhibition of topoisomerase II in cochlear hair cells B) Formation of DNA adducts and generation of reactive oxygen species in the organ of Corti C) Demyelination of the auditory nerve D) Vasospasm of the labyrinthine artery E) Competitive inhibition of potassium channels in hair cells
Answer: B
Cisplatin accumulates in the cochlea, particularly in the stria vascularis and hair cells of the organ of Corti. It forms DNA adducts and generates reactive oxygen species (ROS), leading to apoptosis of outer hair cells. This causes irreversible high-frequency sensorineural hearing loss. Tinnitus is an early warning sign. Risk factors include high cumulative dose, concurrent cranial irradiation, and pre-existing renal impairment (cisplatin is nephrotoxic).
Q74 [MBA] (Microbiology — HIV) — A 28-year-old HIV-positive woman with a CD4 count of 200 cells/µL presents at 32 weeks' gestation with a fever of 38.5°C and cough for 5 days. Her chest X-ray shows bilateral interstitial infiltrates. Which of the following investigations should be performed? Select ALL that apply. A) Sputum for Pneumocystis jirovecii PCR B) Blood cultures C) Sputum for acid-fast bacilli (TB culture) D) Quantitative CMV PCR E) Full blood count and C-reactive protein
Answer: A, B, C, E
This HIV-positive woman with low CD4 count (<200) presents with fever and bilateral interstitial infiltrates, raising concern for opportunistic infections. Pneumocystis jirovecii pneumonia (PCP) is the most likely diagnosis with CD4 < 200 (A). TB is also important to exclude in immunocompromised patients (C). Blood cultures (B) and inflammatory markers (E) help identify bacterial causes. CMV pneumonitis typically occurs at CD4 < 50 and is less likely without retinitis or GI involvement.
Q75 [SBA] (Immunology — Rh) — A 34-year-old RhD-negative woman at 28 weeks' gestation has a routine anti-D prophylaxis injection. She then sustains a significant abdominal trauma from a road traffic accident at 30 weeks. Which of the following is the most appropriate management regarding anti-D prophylaxis? A) No further anti-D needed as she already received prophylaxis at 28 weeks B) Give an additional 500 IU anti-D immediately plus a Kleihauer test C) Repeat routine anti-D at 34 weeks D) Give 1500 IU anti-D without Kleihauer testing E) Check anti-D antibody levels; give additional dose only if levels are low
Answer: B
Any potentially sensitising event in pregnancy (abdominal trauma, antepartum haemorrhage, invasive procedures) in an RhD-negative woman requires additional anti-D prophylaxis regardless of routine antenatal prophylaxis. A Kleihauer test should be performed to quantify the FMH and determine if additional dosing is needed. The standard additional dose is 500 IU, with further doses based on FMH volume. The 28-week prophylaxis provides cover for occult FMH between 28-40 weeks but does not cover acute sensitising events.
Q76 [SBA] (Biochemistry — Enzymes in O&G) — A 35-year-old woman at 16 weeks' gestation is found to have a low PAPP-A (pregnancy-associated plasma protein A) on combined first-trimester screening. Which of the following best describes the function of PAPP-A? A) A protease that cleaves insulin-like growth factor binding proteins (IGFBPs), increasing bioavailable IGF B) A glycoprotein produced by the fetal liver that regulates iron metabolism C) An enzyme involved in placental progesterone synthesis D) A coagulation factor that promotes placental thrombosis E) A cytokine that modulates uterine NK cell activity
Answer: A
PAPP-A is a zinc-binding matrix metalloproteinase produced by the placental syncytiotrophoblast. Its primary function is to cleave insulin-like growth factor binding protein 4 (IGFBP-4), releasing bound IGF for placental and fetal growth. Low PAPP-A levels are associated with impaired placentation and increased risk of pre-eclampsia, fetal growth restriction, and preterm birth. It is measured as part of the first-trimester combined screening for aneuploidy.
Q77 [SBA] (Genetics — Trinucleotide) — A 42-year-old man develops progressive gait ataxia and dysarthria at age 40. His mother died of a similar neurological condition. His 35-year-old sister is asymptomatic. Genetic testing reveals an expanded CAG repeat in the ATXN2 gene. Which of the following inheritance patterns best describes this condition? A) Autosomal dominant with anticipation B) Autosomal recessive with incomplete penetrance C) X-linked recessive D) Mitochondrial inheritance E) Imprinting with paternal transmission
Answer: A
Spinocerebellar ataxia type 2 (SCA2) is caused by CAG trinucleotide repeat expansion in the ATXN2 gene and is inherited in an autosomal dominant pattern. Trinucleotide repeat disorders (Huntington's, SCA, myotonic dystrophy) exhibit anticipation — the number of repeats expands in successive generations, leading to earlier onset and increased severity. The father inherited it from his affected mother, and if his sister inherits the mutation, she may also develop symptoms.
Q78 [SBA] (Embryology — Gonadal development) — At which week of embryonic development does the indifferent gonad begin to differentiate into a testis in the presence of SRY expression? A) Week 4 B) Week 6-7 C) Week 9-10 D) Week 12-14 E) Week 16-18
Answer: B
The indifferent gonad forms at week 5 and begins differentiating into a testis at weeks 6-7 under the influence of SRY expression on the Y chromosome. SRY is expressed in supporting cell precursors, triggering their differentiation into Sertoli cells. Testicular cords form by week 8. In the absence of SRY, the gonad develops into an ovary starting at week 10-12. This early time window explains why abnormalities in SRY or downstream genes cause DSD.
Q79 [SBA] (Statistics — ROC) — A new biomarker for ovarian cancer diagnosis is evaluated. The area under the receiver operating characteristic (ROC) curve is 0.85. Which of the following best interprets this value? A) The test has 85% sensitivity at 100% specificity B) There is a 15% probability that the test will misclassify a patient C) A randomly selected woman with ovarian cancer has a higher test value than a randomly selected woman without the disease 85% of the time D) The test correctly identifies 85% of women with ovarian cancer E) The positive predictive value is 85%
Answer: C
The area under the ROC curve (AUC) represents the probability that the test will rank a randomly chosen diseased individual higher than a randomly chosen non-diseased individual. An AUC of 0.85 indicates good discriminative ability. It is NOT a measure of sensitivity, specificity, or predictive value at any particular threshold. An AUC of 0.5 = no discrimination (coin toss), 1.0 = perfect discrimination.
Q80 [SBA] (Clinical/Surgical — Guidelines) — An RCOG green-top guideline on the management of postpartum haemorrhage (PPH) recommends that all maternity units should have a PPH protocol. A 32-year-old woman has a PPH of 1500 mL following vaginal delivery. According to the RCOG guideline, which of the following should be administered first-line as a second-line uterotonic agent if oxytocin is insufficient? A) Carboprost (PGF2α) 250 µg intramuscularly B) Ergometrine 500 µg intravenously C) Misoprostol 800 µg rectally D) Oxytocin infusion 40 IU in 500 mL saline E) Carbetocin 100 µg intravenously
Answer: C
The RCOG green-top guideline (No. 52) for PPH recommends misoprostol 800 µg rectally as the second-line uterotonic agent when oxytocin is insufficient, as it has a favourable side-effect profile compared to ergometrine (hypertension, nausea) and carboprost (bronchospasm in asthmatics). Oxytocin remains first-line. Carbetocin (a long-acting oxytocin analogue) is an alternative first-line agent at caesarean section but is not the recommended second-line for failed oxytocin.
Q81 [SBA] (Anatomy — Nerve injuries) — A 38-year-old woman undergoes a midurethral sling (tension-free vaginal tape) procedure for stress urinary incontinence. Postoperatively, she reports difficulty voiding and loss of sensation on the medial aspect of the labia majora. Which nerve has most likely been injured? A) Pudendal nerve B) Ilioinguinal nerve C) Genitofemoral nerve D) Perineal branch of the pudendal nerve E) Dorsal nerve of the clitoris
Answer: C
The genitofemoral nerve (L1-L2) supplies sensation to the medial labia majora and the skin over the femoral triangle. During a TVT procedure, the needle is passed through the retropubic space, where it passes close to the genitofemoral nerve as it runs along the psoas muscle. Injury can cause sensory loss over the labia and inner thigh. The ilioinguinal nerve supplies the mons pubis and proximal labia. The pudendal nerve supplies the perineum proper.
Q82 [SBA] (Reproductive Physiology — Parturition) — A 29-year-old woman in established labour has contractions every 2-3 minutes, each lasting 60 seconds. An intrauterine pressure catheter measures the contractions at 80 mmHg. Which of the following correctly describes the relationship between intrauterine pressure, uterine blood flow, and fetal oxygenation during a contraction? A) Uterine blood flow increases during contractions, improving fetal oxygenation B) Uterine blood flow decreases during contractions as myometrial vessels are compressed C) Fetal oxygenation is independent of uterine blood flow D) Uterine blood flow is highest at the peak of a contraction E) Fetal heart rate accelerations are expected in response to hypoxia during contractions
Answer: B
During a uterine contraction, myometrial vessels are compressed, reducing uterine blood flow. At peak contractions of 50-80 mmHg, blood flow can decrease by up to 60%. Normal fetal oxygenation is maintained between contractions. If contractions are too frequent, hypertonic, or the baseline is compromised (e.g., FGR), this intermittent hypoxia can lead to fetal acidosis. This is also the basis for fetal heart rate decelerations.
Q83 [MBA] (Endocrinology — Calcium) — A 35-year-old woman is diagnosed with primary hyperparathyroidism during pregnancy. Serum calcium is 2.9 mmol/L, PTH is elevated. Which of the following are potential maternal and fetal complications of hyperparathyroidism in pregnancy? Select ALL that apply. A) Nephrolithiasis B) Pancreatitis C) Neonatal hypocalcaemia and tetany D) Maternal hypertension E) Polyhydramnios
Answer: A, B, C, D
Primary hyperparathyroidism in pregnancy carries significant risks. Maternal complications include nephrolithiasis (A), pancreatitis (B), hypercalcaemic crisis, and hypertension (D). Fetal/neonatal complications include neonatal hypocalcaemia and tetany (C) due to suppression of the fetal parathyroid glands by maternal hypercalcaemia, and increased risk of miscarriage, FGR, and preterm delivery. Polyhydramnios (E) is not directly associated with hyperparathyroidism.
Q84 [SBA] (Fetal/Neonatal Physiology — Thermoregulation) — A preterm neonate at 27 weeks' gestation is placed under a radiant warmer immediately after delivery. Which of the following best describes the primary mechanism of non-shivering thermogenesis in the newborn? A) Glycolysis in skeletal muscle generating ATP B) Lipolysis of brown adipose tissue via uncoupling protein 1 (UCP1) C) Hepatic gluconeogenesis producing heat as a by-product D) Shivering of skeletal muscles generating frictional heat E) Peripheral vasoconstriction reducing heat loss
Answer: B
Non-shivering thermogenesis in newborns occurs primarily in brown adipose tissue (BAT), which contains abundant mitochondria with uncoupling protein 1 (UCP1). UCP1 uncouples oxidative phosphorylation — instead of ATP synthesis, the proton gradient is dissipated as heat. This is triggered by noradrenaline binding to β3-adrenergic receptors. BAT deposits are located in the interscapular region, axillae, and around the kidneys. Preterm infants have less BAT, making them more vulnerable to hypothermia.
Q85 [SBA] (Pathology — Cervical/endometrial pathology) — A 48-year-old woman with a body mass index of 42 kg/m² presents with intermenstrual bleeding. Endometrial biopsy shows well-differentiated glands with back-to-back architecture, no stromal invasion, and complex branching. Which of the following is the most likely diagnosis? A) Atypical endometrial hyperplasia B) FIGO grade 1 endometrioid adenocarcinoma C) Serous endometrial carcinoma D) Clear cell endometrial carcinoma E) Endometrial polyp with hyperplasia
Answer: B
The description of well-differentiated glands with back-to-back architecture and complex branching is characteristic of FIGO grade 1 endometrioid adenocarcinoma. The key diagnostic feature distinguishing carcinoma from atypical hyperplasia is the presence of confluent glandular architectural complexity with little to no intervening stroma (back-to-back glands). Stromal invasion may not be visible in a biopsy fragment but the architectural complexity ≥ 2 mm confluent area confirms carcinoma. Obesity and unopposed oestrogen are major risk factors.
Q86 [MBA] (Pharmacology — GnRH analogues) — A 35-year-old woman with symptomatic endometriosis is being treated with a GnRH antagonist (relugolix) for 24 weeks. Which of the following are advantages of GnRH antagonists compared to GnRH agonists? Select ALL that apply. A) No initial flare effect with exacerbation of symptoms B) Immediate suppression of gonadotrophins C) Oral administration available D) Less bone mineral density loss E) Better efficacy in reducing endometriosis-associated pain
Answer: A, B, C
GnRH antagonists (relugolix, cetrorelix, ganirelix) competitively block GnRH receptors, causing immediate gonadotrophin suppression without the initial flare (surge) seen with agonists. This avoids the 1-2 week period of symptom exacerbation. Relugolix is orally administered, while most agonists are injections or implants. Bone mineral density loss is comparable between antagonists and agonists when used for the same duration. Pain reduction efficacy is similar between the two classes.
Q87 [SBA] (Microbiology — TORCH) — A 32-year-old woman at 36 weeks' gestation presents with a painful vesicular rash on the vulva. She has no prior history of genital herpes. PCR of vesicular fluid is positive for HSV-2. Which of the following is the most appropriate management? A) Oral aciclovir 400 mg three times daily for 5 days; plan vaginal delivery B) Intravenous aciclovir for 14 days C) Start aciclovir and plan elective caesarean section at 39 weeks D) Start aciclovir and plan elective caesarean section at 38 weeks E) No antiviral treatment; elective caesarean section at 38 weeks
Answer: D
Primary genital HSV acquired in the third trimester carries a very high risk (40-60%) of neonatal transmission. Management includes oral aciclovir 400 mg TDS (or IV for severe cases) and planning elective caesarean section at 38-39 weeks to reduce the risk of neonatal herpes. Even if lesions have resolved by term, caesarean section is recommended for primary HSV in the third trimester because viral shedding may still occur. Suppressive aciclovir from 36 weeks is recommended for women with recurrent HSV.
Q88 [SBA] (Immunology — Autoimmunity) — A 32-year-old woman with known autoimmune thyroid disease (Hashimoto's thyroiditis) is 8 weeks pregnant. She is euthyroid on levothyroxine. Which of the following maternal autoantibodies is most associated with an increased risk of miscarriage and preterm birth? A) Anti-thyroglobulin antibodies (TgAb) B) TSH receptor antibodies (TRAb) C) Thyroid peroxidase antibodies (TPOAb) D) Anti-SSA (Ro) antibodies E) Anti-dsDNA antibodies
Answer: C
Thyroid peroxidase antibodies (TPOAb) are associated with an increased risk of miscarriage and preterm birth, even in women who are euthyroid. The mechanism is thought to involve subtle thyroid dysfunction or direct immune effects on the placenta. TPOAb positivity affects approximately 5-15% of pregnant women. TSH receptor antibodies (TRAb) are associated with Graves' disease and can cause fetal/neonatal thyrotoxicosis. Anti-SSA is associated with congenital heart block.
Q89 [SBA] (Biochemistry — Enzymes in O&G) — A woman undergoes ovulation induction with gonadotrophins. During monitoring, a high level of which of the following enzymes in follicular fluid is considered a marker of oocyte maturity and successful ovulation? A) Alkaline phosphatase B) Hyaluronidase C) Plasminogen activator D) Lactate dehydrogenase E) Cyclooxygenase-2
Answer: C
Plasminogen activator (specifically tissue-type, tPA) is a key enzyme in the ovulatory cascade. It converts plasminogen to plasmin, which then activates matrix metalloproteinases that degrade the follicular wall, allowing oocyte release. High levels of plasminogen activator in follicular fluid correlate with oocyte maturity and successful ovulation. Hyaluronidase is involved in cumulus expansion but is not the primary maturity marker. COX-2 produces prostaglandins involved in ovulation.
Q90 [MBA] (Genetics — BRCA) — A 40-year-old woman with a BRCA1 mutation is counselled about risk-reducing options. Which of the following are established risk-reduction strategies for BRCA1 carriers? Select ALL that apply. A) Risk-reducing bilateral salpingo-oophorectomy (RRSO) B) Risk-reducing bilateral mastectomy C) Tamoxifen for breast cancer chemoprophylaxis D) Combined oral contraceptive pill for ovarian cancer risk reduction E) Annual CA-125 and transvaginal ultrasound screening
Answer: A, B, C
RRSO reduces ovarian cancer risk by 80-95% and breast cancer risk by 50% in premenopausal BRCA carriers. Risk-reducing mastectomy reduces breast cancer risk by >90%. Tamoxifen reduces contralateral breast cancer risk in BRCA carriers. The COCP reduces ovarian cancer risk but is not recommended for chemoprophylaxis in BRCA carriers due to potential breast cancer risk. Annual CA-125 and ultrasound (E) is a screening option for those who decline RRSO, not risk-reduction.
Q91 [SBA] (Embryology — Congenital anomalies) — A newborn with a 46,XY karyotype is found to have female external genitalia, a blind-ending vagina, no uterus, and intra-abdominal testes. Which of the following conditions best describes this presentation? A) 5α-reductase deficiency B) Complete androgen insensitivity syndrome (CAIS) C) 17α-hydroxylase deficiency D) Swyer syndrome (46,XY complete gonadal dysgenesis) E) Persistent Müllerian duct syndrome
Answer: B
Complete androgen insensitivity syndrome (CAIS) results from a mutation in the androgen receptor gene. The testes produce normal androgen levels, but target tissues cannot respond. External genitalia develop as female, the vagina is blind-ending, and Müllerian structures (uterus, fallopian tubes) are absent due to anti-Müllerian hormone (AMH) from the testes. 5α-reductase deficiency causes ambiguous genitalia, not complete female phenotype. Swyer syndrome has streak gonads, not testes.
Q92 [SBA] (Statistics — Bias) — A study compares pregnancy outcomes between women who received epidural analgesia during labour and those who did not. The results show a higher rate of instrumental delivery in the epidural group. However, women who chose epidural were also more likely to have induced labour and longer labours. This is an example of which type of bias? A) Berksonian bias B) Confounding by indication C) Recall bias D) Publication bias E) Observer bias
Answer: B
Confounding by indication occurs when the exposure (epidural) is associated with the indication for its use (longer/more painful labour), which itself is associated with the outcome (instrumental delivery). Women who labour longer or have inductions are both more likely to request epidurals and more likely to have instrumental deliveries. Randomised trials (e.g., COMET trial) are needed to separate the causal effect of epidural from the confounding effect of labour characteristics.
Q93 [SBA] (Clinical/Surgical — Instruments) — A surgeon performing a caesarean section uses a Bonanno catheter for bladder drainage. Which of the following best describes the distinguishing feature of a Bonanno catheter? A) It has a 30-mL balloon and a larger drainage lumen B) It is a suprapubic catheter with a flexible introducer needle and a pigtail retention mechanism C) It is a three-way catheter for continuous bladder irrigation D) It is a female-length (shorter) urethral catheter E) It is a silicone-coated catheter for long-term use
Answer: B
The Bonanno catheter is a suprapubic catheter system that uses a flexible introducer needle with a peel-away sheath. The catheter has a pigtail coil (J-tip) that retains it in the bladder without a balloon. It is commonly inserted during caesarean section if long-term bladder drainage is anticipated or if urethral catheterisation is contraindicated. It is not a urethral catheter (contra A, D). Three-way catheters are for irrigation (contra C).
Q94 [SBA] (Anatomy — Perineum) — A 30-year-old woman sustains a childbirth-related injury that results in faecal incontinence. Anorectal physiology studies confirm isolated injury to the external anal sphincter. Which nerve provides the primary motor innervation to the external anal sphincter? A) Inferior rectal nerve (branch of the pudendal nerve) B) Perineal branch of the pudendal nerve C) Pelvic splanchnic nerves (S2-S4) D) Nerve to levator ani (S3-S4) E) Ilioinguinal nerve
Answer: A
The external anal sphincter (EAS) is a skeletal muscle innervated by the inferior rectal nerve (also called the inferior haemorrhoidal nerve), which is a terminal branch of the pudendal nerve (S2-S4). The internal anal sphincter (smooth muscle) is innervated by sympathetic (L1-L2 via hypogastric nerve) and parasympathetic (S2-S4 via pelvic splanchnic) fibres. Injury to the EAS is a common cause of passive faecal incontinence after vaginal delivery.
Q95 [SBA] (Reproductive Physiology — Lactation) — A 28-year-old breastfeeding woman reports that her milk production is inadequate. Domperidone is prescribed as a galactagogue. Which of the following best describes the mechanism of domperidone in increasing milk supply? A) Dopamine D2 receptor antagonist, increasing prolactin release from the anterior pituitary B) Oxytocin receptor agonist, enhancing milk let-down C) Prolactin receptor agonist, directly stimulating milk synthesis D) Dopamine D2 receptor agonist, suppressing prolactin-inhibiting factor E) Serotonin reuptake inhibitor, modulating mood and lactation
Answer: A
Domperidone is a dopamine D2 receptor antagonist that does not cross the blood-brain barrier significantly. By blocking dopamine D2 receptors in the anterior pituitary (where dopamine normally acts as prolactin-inhibiting factor), it increases prolactin secretion. Prolactin is the primary hormone driving milk synthesis (lactogenesis). Domperidone is used off-label as a galactagogue when non-pharmacological measures fail. Other dopamine antagonists like metoclopramide have similar but less favourable profiles.
Q96 [MBA] (Fetal/Neonatal Physiology — Cord gases) — Umbilical cord blood gas analysis is performed after a difficult delivery. Which of the following values are consistent with a normal umbilical artery cord gas at term? Select ALL that apply. A) pH 7.25 B) pCO2 55 mmHg C) pO2 30 mmHg D) Base excess −5 mmol/L E) Lactate 8 mmol/L
Answer: A, B, C, D
Normal umbilical artery cord gas values at term: pH 7.20-7.30, pCO2 40-55 mmHg, pO2 15-30 mmHg, base excess 0 to −8 mmol/L, lactate < 6 mmol/L. Options A (7.25), B (55), C (30), and D (−5) are all within normal range. Lactate of 8 mmol/L (E) is elevated and suggests metabolic acidosis/ anaerobic metabolism. Uteroplacental insufficiency is suspected when pH < 7.00, base excess < −12 mmol/L, or lactate > 8-10 mmol/L.
Q97 [SBA] (Pathology — Ovarian tumours) — A 65-year-old woman presents with a pelvic mass. Histology of the oophorectomy specimen shows a tumour with Schiller-Duval bodies and a reticular pattern. Serum AFP is markedly elevated. Which of the following is the most likely diagnosis? A) Dysgerminoma B) Yolk sac tumour C) Immature teratoma D) Choriocarcinoma E) Granulosa cell tumour
Answer: B
Yolk sac tumour (also called endodermal sinus tumour) is a malignant germ cell tumour characterised by Schiller-Duval bodies (glomerulus-like structures with a central fibrovascular core lined by cuboidal cells) and a reticular (honeycomb) pattern. It secretes AFP. It typically occurs in young women and children. Dysgerminomas have lymphoid stroma and elevate LDH. Immature teratomas contain immature neural tissue. Choriocarcinoma produces hCG.
Q98 [SBA] (Pharmacology — Immunosuppressants) — A 34-year-old woman with ulcerative colitis on maintenance azathioprine is planning pregnancy. She is concerned about the safety of continuing her medication. Which of the following is the most accurate counselling regarding azathioprine use in pregnancy? A) Azathioprine is absolutely contraindicated in pregnancy B) Azathioprine is considered relatively safe in pregnancy and can be continued C) Azathioprine should be stopped 3 months before conception D) Azathioprine should be switched to methotrexate before pregnancy E) Azathioprine causes a specific embryopathy syndrome
Answer: B
Azathioprine is considered relatively safe in pregnancy and can be continued at the lowest effective dose. The fetal liver lacks the enzyme to convert azathioprine to its active metabolite (6-mercaptopurine), providing a degree of fetal protection. Studies do not show a significant increase in congenital anomalies above baseline. Methotrexate (C) is teratogenic and contraindicated in pregnancy. Mycophenolate mofetil (not azathioprine) is associated with a specific embryopathy syndrome.
Q99 [SBA] (Microbiology — Maternal sepsis) — A 26-year-old woman develops fever, abdominal pain, and diarrhoea at 30 weeks' gestation. She recalls eating unpasteurised soft cheese. Blood cultures grow Gram-positive rods that are beta-haemolytic and exhibit tumbling motility on wet preparation. Which of the following is the most likely causative organism? A) Group B Streptococcus B) Escherichia coli C) Listeria monocytogenes D) Clostridium perfringens E) Campylobacter jejuni
Answer: C
Listeria monocytogenes is a Gram-positive rod that exhibits characteristic tumbling motility at room temperature. It is a foodborne pathogen associated with unpasteurised dairy products, deli meats, and soft cheeses. In pregnancy, listeriosis can cause maternal flu-like illness, sepsis, and can lead to chorioamnionitis, preterm labour, fetal loss, or early-onset neonatal sepsis. It crosses the placenta readily. Treatment is IV ampicillin plus gentamicin.
Q100 [SBA] (Statistics — Bias) — A study reports that women who had a previous caesarean section have a 60% chance of a successful vaginal birth after caesarean (VBAC). However, the study was conducted at a tertiary referral centre that manages high-risk pregnancies. Which type of bias is most likely to affect the generalisability of these results? A) Selection bias B) Referral bias (tertiary care bias) C) Detection bias D) Recall bias E) Lead-time bias
Answer: B
Referral bias (also called tertiary care or admission rate bias) occurs when a study conducted in a specialised centre includes a higher proportion of complex or high-risk cases than the general population. The 60% VBAC success rate from a tertiary centre may underestimate the true success rate in the general (lower-risk) population. Conversely, some outcomes may appear worse than in the community. This limits external validity (generalisability) of the findings.