Diagnosis of vasa previa with endovaginal color Doppler and power Doppler sonography: Report of two cases

Vasa previa is a rare anomaly of chorionic development in which unprotected umbilical arteries and veins traverse the lower uterine segment at or near the internal cervical os, ahead of the presenting fetal part. Vasa previa is associated with one of the following: velamentous cord insertion, marginal cord insertion, or bilobed placenta (e.g., succenturiate placental lobe). Perinatal mortality is high owing to vessel rupture after spontaneous or iatrogenic rupture of membranes. Diagnosis prior to the onset of labor could prevent fetal morbidity and mortality. We report two cases in which the diagnosis was made antepartum with endovaginal color Doppler and power Doppler sonography.