Is Neonatal Risk From Vasa Previa Preventable? The 20-Year Experience From a Single Medical Center

Abstract

Vasa previa, a rare complication of pregnancy, has an estimated incidence of 1/1000 to 1/5000 births. A number of prospective studies have demonstrated that the majority of cases can be diagnosed prenatally using transvaginal sonography. One multicenter retrospective study showed that prenatal diagnosis reduced perinatal mortality from 56% to 3%. The present retrospective study evaluated the effect of the prenatal detection of vasa previa by prenatal sonography on neonatal outcomes over two 10-year periods (1988-1997 and 1998-2007). Data on all cases of vasa previa diagnosed at a single institution were retrospectively reviewed for obstetrical history, method of conception, sonographic scans, delivery mode, and neonatal outcome (Apgar score and cord blood gas). A total of 19 confirmed cases of vasa previa (21 neonates) were identified during the 20-year study period, which represents an incidence of 1.7 per 10,000 deliveries. Ten (52.6%) cases of vasa previa were diagnosed prenatally. A comparison of the neonatal outcomes of cases in which the diagnosis was and was not known prenatally showed a higher proportion of neonates with 1-minute Apgar score ≤5 and cord blood pH 0.05 for both). The investigators conclude from these findings that prenatal mid-gestation sonographic screening for vasa previa should be performed in women at normal risk as well as higher risk. The data suggest that universal screening will increase the rate of prenatal detection and thereby, improve the obstetric outcome.