Prenatal diagnosis of vasa previa presenting as amniotic band. 'A not so innocent amniotic band'.

We describe a case in which the early antepartum diagnosis of vasa previa was made in an asymptomatic patient by means of color Doppler ultrasonography. A woman, gravida 3 para 1 at 22 weeks' gestation, was diagnosed as having an anterior low-lying placenta, a velamentous cord insertion and an amniotic band with vessels traversing the internal cervical os towards a succenturiate lobe. At the 39th week, a Cesarean section was performed and a healthy female baby was born. Transvaginal color Doppler flow imaging facilitated the accurate diagnosis of this condition.