Obstetrics
Core concepts
The obstetric content of the qualifying exam rewards a physiologic, timeline-based approach. Master the definitions and management thresholds for hypertensive disorders (gestational hypertension vs. preeclampsia with and without severe features), the diagnosis and inpatient management of preterm labor, and the categorization of postpartum hemorrhage by timing and cause (the "Four T's": tone, trauma, tissue, thrombin). Know the fetal heart rate interpretation framework - baseline, variability, accelerations, decelerations - and the difference between category I, II, and III tracings, because management questions hinge on categorization. Also be solid on gestational diabetes screening and thresholds, Rh alloimmunization prophylaxis, and the major causes of maternal mortality (hemorrhage, thromboembolism, hypertension, sepsis, cardiomyopathy).
Traps
Questions love near-miss distractors. Watch for: (1) treating chronic hypertension as preeclampsia when proteinuria and severe features are absent; (2) confusing variable decelerations (cord compression) with late decelerations (uteroplacental insufficiency) - the timing relative to contractions is the key; (3) recommending delivery when expectant management is appropriate (e.g., preterm premature rupture of membranes at 32 weeks without infection); (4) forgetting magnesium sulfate for seizure prophylaxis in preeclampsia with severe features, not just treatment of eclampsia.
Worked example / rule of thumb
A patient at 34 weeks has BP 158/102 on two occasions four hours apart, platelets 95,000, and AST 80. She has preeclampsia with severe features (severe-range BP, thrombocytopenia, transaminitis) and, at ≥34 weeks, delivery is indicated after magnesium sulfate and antihypertensive therapy. Rule of thumb: severe features trump gestational age once you reach 34 weeks; below that, stabilize and individualize.