Key Concepts
Overview & Classification
Placenta previa: Placenta implanted over or adjacent to the internal cervical os. Incidence: 1 in 200–250 pregnancies. Risk increases with prior C-section (scarred lower uterine segment attracts abnormal placentation). The most dangerous type of antepartum hemorrhage because it is painless and can be massive. On the exam, writers often pair stable-sounding options with unstable data—notice the mismatch before you commit. If the stem names a license or role, reread that line; scope errors are classic trap answers even when the clinical topic is familiar. Run a 60-second scan: breathing work and oxygenation, perfusion and end organs, neuro baseline, likely infection sources, and devices that can fail quietly. When two answers feel partly right, pick the one that reduces imminent harm and matches orders for the role you were given. Train yourself to state the primary risk in one short phrase before you read the options so distractors do not rewrite your priority list. On the exam, writers often pair stable-sounding options with unstable data—notice the mismatch before you commit. If the stem names a license or role, reread that line;...