Reproductive Endocrinology and Infertility
Domain 6 - Reproductive Endocrinology and Infertility
This domain tests the couple's work-up, ovulation induction, PCOS and hyperprolactinaemia. Exam questions reward correct first-line choices and correct interpretation of semen analysis and hormone panels.
Core rules
- Infertility: 12 months of unprotected intercourse; investigate at 6 months if the woman is ≥35 or has known pathology.
- Work-up of the couple: semen analysis, ovulation confirmation (cycle history, mid-luteal progesterone), tubal patency (HSG or laparoscopy), plus TSH and prolactin.
- WHO semen reference (5th/6th edition): volume ≥1.4 mL, concentration ≥16 million/mL, total motility ≥42%, progressive motility ≥30%, normal morphology ≥4% (strict criteria).
- PCOS (Rotterdam): two of three - oligo/anovulation, clinical or biochemical hyperandrogenism, polycystic ovarian morphology. Exclude thyroid disease, hyperprolactinaemia and congenital adrenal hyperplasia.
- Ovulation induction in PCOS: weight loss first; letrozole is superior to clomiphene for live birth; metformin as adjunct in insulin resistance; gonadotrophins or laparoscopic ovarian drilling if resistant; IVF if tubal or male factor coexists.
- Clomiphene 50–150 mg on days 2–6, with follicular monitoring to avoid multiple pregnancy and OHSS.
- Hyperprolactinaemia: exclude pregnancy, drugs and hypothyroidism before cabergoline; image the pituitary if markedly elevated.
Worked example
A 32-year-old with PCOS, BMI 34 and no menses for four months wants to conceive. Plan: lifestyle and weight reduction, then letrozole 2.5–5 mg for five days with ultrasound monitoring of follicular growth; metformin added for insulin resistance. Clomiphene is not the first choice, and gonadotrophins are reserved for letrozole failure.
Traps
Quoting old WHO 1999 semen cut-offs; treating hyperprolactinaemia before excluding pregnancy; starting gonadotrophins before weight loss; forgetting to check the partner.