Reproductive Endocrinology and Infertility
Core concepts
REI integrates hypothalamic-pituitary-ovarian physiology with clinical disorders: polycystic ovary syndrome, anovulation, hyperprolactinemia, thyroid dysfunction, premature ovarian insufficiency, endometriosis-related infertility, and male factor infertility. Know the infertility workup (semen analysis, ovulation assessment, tubal patency, uterine evaluation) and when to escalate to assisted reproduction. Understand ovulation induction agents, their risks (multiple gestation, ovarian hyperstimulation syndrome), and the approach to recurrent pregnancy loss.
Traps
- PCOS diagnosis: requires two of three Rotterdam criteria (oligo/anovulation, hyperandrogenism, polycystic ovaries) after excluding other causes; do not diagnose on ultrasound alone.
- Hyperprolactinemia: evaluate with repeat prolactin and consider medications, pituitary adenoma, and hypothyroidism; treat before assuming infertility is unexplained.
- Ovarian reserve testing: AMH and antral follicle count estimate reserve but do not predict spontaneous conception perfectly.
- Ovarian hyperstimulation syndrome: presents with ovarian enlargement, ascites, hemoconcentration; prevention with protocol adjustment and monitoring.
- Recurrent pregnancy loss: evaluate for uterine anomalies, antiphospholipid syndrome, and parental karyotype after appropriate thresholds.
Worked example / rule of thumb
A patient with irregular cycles, hirsutism, and polycystic ovaries. Rule of thumb: PCOS is a diagnosis of exclusion; confirm two Rotterdam criteria and exclude thyroid disease, hyperprolactinemia, and nonclassic congenital adrenal hyperplasia before treating.
Study strategy
Map the HPO axis and pair each level of dysfunction with its lab pattern and treatment.