EP16.23: Prenatal sonographic diagnosis of vasa previa: clinical features and pregnancy outcome

To assess the prenatal sonographic features of vasa previa and analyse the risk factors of pregnancy outcome. This was a retrospective descriptive study that included all pregnancies that were complicated by vasa previa. Data regarding maternal obstetric courses, prenatal ultrasound findings and newborn status were collected. 32 cases were diagnosed by ultrasound scanning antenatally, including 29 singleton and 2 cases of dichorionic-diamniotic twins and 1 case of monochorionic-diamniotic twins. 32 cases of vasa previa were diagnosed at a mean gestational age of 25 weeks (15 - 34 weeks). Most of these cases (31/32, 96.9%) had the identifiable placental and/or maternal risk factors that have been reported to include placenta previa, low-lying placenta, succenturiate placenta or an accessory placental lobe, multiple gestation, and in vitro fertilization. One case of monochorionic-diamniotic twins died in utero at 37 weeks of gestation. 31 cases were delivered by elective Caesarean section after demonstration of fetal pulmonary maturity at a mean gestational age of 34 weeks (28 - 37 weeks). This study confirms most current reported placental and/or maternal risk factors of vasa previa. Prenatal diagnosis of vasa previa is beneficial to clinical risk management and good pregnancy outcome.