Two cases of vasa previa diagnosed prenatally using three-dimensional ultrasonography.

We report two cases in which we describe the impact of sonography (US) in the management of vasa previa. In the first case, with two-dimensional US, the diagnosis of vasa previa was made at 21 weeks gestation. In the second case, using three-dimensional US, the diagnosis of vasa previa was made at 19 weeks gestation. An elective Cesarean section was carried out at 34 weeks in both cases. Diagnosis of vasa previa is critical when low-lying placenta or velamentous insertion of the umbilical cord is detected during the pregnancy.