Society for Maternal-Fetal Medicine (SMFM) Consult Series

Vasa previa occurs when fetal blood vessels that are unprotected by the umbilical cord or placenta run through the amniotic membranes and traverse the cervix. If membranes rupture, these vessels may rupture, with resultant fetal hemorrhage, exsanguination, or even death. Prenatal diagnosis of vasa previa by ultrasound scans is approximately 98%. Approximately 28% of prenatally diagnosed cases result in emergent preterm delivery. Management of prenatally diagnosed vasa previa includes antenatal corticosteroids between 28-32 weeks of gestation, considerations for preterm hospitalization at 30-34 weeks of gestation, and scheduled delivery at 34-37 weeks of gestation.