Late pregnancy bleeding.

Effective management of vaginal bleeding in late pregnancy requires recognition of potentially serious conditions, including placenta previa, placental abruption, and vasa previa. Placenta previa is commonly diagnosed on routine ultrasonography before 20 weeks' gestation, but in nearly 90 percent of patients it ultimately resolves. Women who have asymptomatic previa can continue normal activities, with repeat ultrasonographic evaluation at 28 weeks. Persistent previa in the third trimester mandates pelvic rest and hospitalization if significant bleeding occurs. Placental abruption is the most common cause of serious vaginal bleeding, occurring in 1 percent of pregnancies. Management of abruption may require rapid operative delivery to prevent neonatal morbidity and mortality. Vasa previa is rare but can result in fetal exsanguination with rupture of membranes. Significant vaginal bleeding from any cause is managed with rapid assessment of maternal and fetal status, fluid resuscitation, replacement of blood products when necessary, and an appropriately timed delivery.