The association of gestational age at delivery with neonatal outcomes in prenatally diagnosed vasa previa

Objective: To report on the association of gestational age at delivery and neonatal outcomes in prenatally diagnosed vasa previa. Methods: A retrospective cohort study at two academic/community hybrid hospitals, covered by the same maternal-fetal medicine group. Neonatal characteristics and outcomes were compared between cases of prenatally diagnosed vasa previa delivered at gestational age <36weeks and >= 36weeks. Results: We identified 59 cases of vasa previa, of which 2 were excluded, one due to delivery at 28weeks for preeclampsia, and one because it was not diagnosed prenatally, leaving 57 pregnancies in our study. There were 2 sets of twins. As such, there were 59 newborns. The mean gestational age at delivery was 35.08 (+/- 0.27) weeks for those delivered at <36weeks, and 36.11 (+/- 0.16) weeks for those delivered >= 36weeks. All cases were delivered by cesarean. Delivery at >= 36weeks was associated with greater mean birth weight (2774g (+/- 376.3g)) compared with 2292.5g (+/- 406.8g) for those babies delivered at <36weeks (p<0.001). In addition, there were shorter hospital stays for the babies delivered at >= 36weeks (median 3days; interquartile range (IQR) 3,3) when compared with those delivered at <36weeks (median 13days; IQR 3,20). In addition, delivery at >= 36weeks was associated with lower rates of intubation, jaundice and respiratory distress syndrome. Importantly, no cases of rupture of the membranes or vessel rupture occurred in either group. Conclusion: Our study suggests that delivery at >= 36weeks is safe for asymptomatic patients with prenatally diagnosed vasa previa, and may be associated with improved neonatal outcomes. We suggest that stable asymptomatic patients with prenatal diagnosis of vasa previa be delivered at 36weeks rather than at less than 36weeks. This will reduce neonatal morbidity with no apparent increased risk to babies.