system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
A 30-year-old woman, gravida 4, para 3, at 39 weeks' gestation comes to the hospital 20 minutes after the onset of vaginal bleeding. She has not received prenatal care. Her third child was delivered by lower segment transverse cesarean section because of a footling breech presentation. Her other two children were delivered vaginally. Her temperature is 37.1°C (98.8°F), pulse is 86/min, respirations are 18/min, and blood pressure is 132/74 mm Hg. The abdomen is nontender, and no contractions are felt. The fetus is in a vertex presentation. The fetal heart rate is 96/min. Per speculum examination reveals ruptured membranes and severe bleeding from the external os. Which of the following is the most likely diagnosis?
assistant
Ruptured vasa previa