Vasa previa: the impact of prenatal diagnosis on outcomes.

Objective: To evaluate outcomes and predictors of neonatal survival in pregnancies complicated by vasa previa and to compare outcomes in prenatally diagnosed cases of vasa previa with those not diagnosed prenatally.

Methods: We performed a multicenter study of 155 pregnancies complicated by vasa previa. Cases were obtained from the Vasa Previa Foundation and 6 large hospitals. Comparisons were made between groups based on prenatal diagnosis status and neonatal survival.

Results: The overall perinatal mortality was 36% (55 of 155). In 61 cases (39%), vasa previa was diagnosed prenatally; 59 of 61 (97%) infants from these pregnancies survived compared with 41 of 94 (44%) in cases not diagnosed prenatally (P <.001). Median 1- and 5-minute Apgar scores in cases diagnosed prenatally were 8 and 9, respectively, compared with 1 and 4 among survivors in cases not diagnosed prenatally (P <.001). More than half (24 of 41) of surviving neonates born to women without prenatal diagnosis required blood transfusions compared with 2 of 59 diagnosed prenatally (P <.001). Multivariable logistic regression analysis showed that the only significant predictors of neonatal survival were prenatal diagnosis (P <.001) and gestational age at delivery (P =.01).

Conclusions: Good outcomes with vasa previa depend primarily on prenatal diagnosis and cesarean delivery at 35 weeks of gestation or earlier should rupture of membranes, labor, or significant bleeding occur.