Evidence-based Diagnosis and Treatment of Vasa Previa.

Vasa previa is an abnormality of the umbilical cord and fetal membranes that affects ∼1 in 1300 pregnancies. The diagnosis is made by visualization of velamentous fetal vessels coursing within the membranes over the cervix unprotected by Wharton jelly or placenta. When it is not diagnosed prenatally, it is associated with a high risk of fetal death. Prenatal diagnosis of vasa previa using ultrasound, followed by close surveillance, and appropriately timed late preterm delivery by cesarean is associated with intact survival in >95% of cases. In this review, we review epidemiology, risk factors, diagnosis, and management of patients with vasa previa.