Answer :USMLE step 2 Mcq 282 :A 19 year old presented to Casualty at 34 weeks gestation with severe vaginal bleeding and lower abdominal pain. Her obstetric history was-UKMLA PLAB AMC USMLE Prometric MCQ

Answer :USMLE step 2 Mcq 282 :A 19 year old presented to Casualty at 34 weeks gestation with severe vaginal bleeding and lower abdominal pain. Her obstetric history was

on Tuesday, December 21, 2010

Correct Answer: D

Explanation:
Vasa previa is caused by a velamentous insertion of the umbilical cord.This occurs when the umbilical vessels separate prior to reaching the placental surface. When the umbilical vessels, lacking the structural support of an intact umbilical cord, present in advance of the fetal head, vasa previa is diagnosed. The incidence of vasa previa is 1:3000 deliveries. It is associated with placental previa (1:250), succenturiate lobes, and multiple gestation. The antenatal diagnosis of vasa previa is rare; it is usually diagnosed during labor. Clinically, vasa previa presents with heart rate decelerations. or bradycardia. Vasa previa (velamentous insertion of the cord). Delivery should be by scheduled C-section. If pregnancy is allowed to progress to term, spontaneous rupture of membrane or amniotomy should be averted because it could lead to fatal bleeding for fetus and possibly mother.

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