USMLE® Step 1 style questions USMLE
A 33-year-old woman, gravida 3 para 2, is admitted to the labor and delivery unit with active contractions every 3-5 minutes. Her previous births were via cesarean sections. One hour later, she gives birth to a healthy child. Thirty minutes after delivery, the placenta has still not been delivered. Manual extraction of the retained placenta is performed and leads to profuse bleeding. The patient’s temperature is 37.0°C (98.6°F), pulse is 120/min, and blood pressure is 85/60 mmHg. Oxygen saturation is 95% on room air. On physical examination, the uterus is firm and nontender. Hemoglobin is 9 g/dL and platelet count is 220,000/mm3. Which of the following is the most likely underlying mechanism for this patient’s bleeding?
Placenta accreta exam links
Placenta accreta occurs when all or part of the placenta attaches abnormally to the myometrium (the muscular layer of the uterine wall). Risk factors for placenta accreta include the number of previous cesarean deliveries, uterine surgery, advancing maternal age, and multiparity.
Three grades of abnormal placental attachment are defined according to the depth of invasion: Accreta: chorionic villi attach to the myometrium, rather than being restricted within the decidua basalis Increta: chorionic villi invade into the myometrium Percreta: chorionic villi invade through the myometrium.