(1047) Neonatal outcomes among pregnancies complicated by vasa previa: a California population-based cohort study

Objective:
Vasa previa is a rare condition, affecting 1/2500 pregnancies. However, it is a diagnosis associated with severely adverse maternal and neonatal outcomes. Due to this high concern for morbidity, practices around the ideal timing of delivery for vasa previa vary. The objective of this study is to examine the association between key neonatal outcomes by gestational age at the time of delivery for a contemporary cohort.

Study Design:
This is a retrospective cohort study using California’s linked vital statistics-hospital discharge data (2008 and 2020). We included singleton births with gestational age of 32-36 weeks, among individuals with a diagnosis of vasa previa who were hospitalized before delivery. Vasa previa was identified using ICD-9 and ICD-10 diagnostic codes. Maternal and neonatal outcomes were compared between two consecutive weeks of gestational age using chi-square tests and multivariate Poisson regression.

Results:
A total of 760 cases met inclusion criteria. Rates of adverse neonatal outcomes were observed to decline with increasing gestational age. For example, the rate of RDS decreased from 61.9% at 32 weeks to 7.1% at 36 weeks. Rates of Apgar score < 7 declined from 4.9% at 33 weeks to 1.9% at 35 weeks. In regression models, delivery at 35 vs. 34 weeks was associated with lower risk of RDS (aRR 0.42, 95% CI 0.30 - 0.59) and jaundice (aRR 0.70, 95% CI 0.60 - 0.81). Delivery at 36 vs. 35 weeks did not show a statistically significant difference for any of the outcomes.

Conclusion:
Among patients hospitalized due to vasa previa before delivery, neonatal outcomes improved incrementally as gestational age advanced from 32 to 35 weeks, though no significant benefits were noted with delivery at 36 vs 35 weeks. These findings highlight the importance of balancing risks of prematurity with potential neonatal morbidity when determining optimal age at delivery.