Maternal-Fetal Medicine and High-Risk Obstetrics
Hypertensive disorders dominate this domain. Distinguish chronic hypertension (before 20 weeks or persisting beyond 12 weeks postpartum), gestational hypertension (new after 20 weeks without proteinuria or organ dysfunction) and pre-eclampsia. Severe features are blood pressure of 160/110 mmHg or more, platelets below 100, transaminases more than twice normal, creatinine above 1.1 mg/dL or doubling, pulmonary oedema, or new cerebral or visual symptoms. Delivery at 37 weeks is advised for pre-eclampsia without severe features; at 34 weeks or more with severe features, delivery is recommended after stabilisation with magnesium sulphate and antihypertensives.
Gestational diabetes is screened at 24-28 weeks; lifestyle measures, then metformin or insulin, follow. Fetal growth restriction (estimated weight below the 10th centile) requires umbilical artery Doppler, and absent or reversed end-diastolic flow mandates delivery. Anti-D prophylaxis is given to Rh-negative unsensitised women at 28 weeks, after sensitising events, and within 72 hours of delivery of an Rh-positive infant.
Traps: assuming pre-eclampsia always has proteinuria; missing HELLP syndrome, which can occur with normal blood pressure; using magnesium for blood pressure control rather than seizure prophylaxis; and forgetting that low-dose aspirin (81-150 mg) should start at 12-16 weeks in high-risk women.
Rule of thumb: pre-eclampsia with severe features at 34 weeks or beyond means deliver; without severe features, expectant management to 37 weeks.