RESUMO
Vasa previa is said to occur when fetal vessels, unsupported by placenta or umbilical cord, transverse the menbranes over the cervix, below the presenting part. It is typically caused by velamentous insertion of the umbilical cord with fetal vessels between the cervix and presenting part. Bilobed or succenturiate placentas also can be associated with aberrant vasculature over the internal cervical os. Vasa previa has an incidence of approximately one per 2,000-5,000 deliveries. It has a high fetal mortality due to fetal exsanguination resulting from fetal vessels tearing when the menbranes rupture. So Prenatal detection of vasa previa is very important. We believe transvaginal ultrasound in combination with color Doppler is the most effective tool in the antenatal diagnosis of vasa previa. Recently, we experienced one case of vasa previa accompanied by succenturiate placenta diagnosed prenatally by color Doppler and transvaginal sonography. Here we report our experience with a literature review.