Effectiveness of timing strategies for delivery of individuals with vasa previa.

OBJECTIVE: To compare strategies for the timing of delivery in patients with ultrasonographic evidence of vasa previa.

METHODS: A decision tree was designed comparing 11 strategies for delivery timing in a patient with vasa previa. The strategies ranged from a scheduled delivery at 32, 33, 34, 35, 36, 37, 38, or 39 weeks of gestation to a scheduled delivery at 36, 37, or 38 weeks of gestation only after amniocentesis confirmation of fetal lung maturity. Outcomes factored into the model included perinatal mortality, infant mortality, respiratory distress syndrome, mental retardation, and cerebral palsy.

RESULTS: A scheduled delivery at 34 weeks of gestation was the preferred strategy and resulted in the highest quality-adjusted life-years under the base-case assumptions. Sensitivity analyses demonstrated that the optimal gestational age for delivery was dependent on certain estimates in the model, although in most circumstances remained at 34 or 35 weeks of gestation. Under all circumstances, strategies incorporating confirmation of fetal lung maturity failed to result in a better outcome than strategies that incorporated delivery at the same gestational age without amniocentesis.

CONCLUSION: This decision analysis suggests that for women with a vasa previa, delivery at 34-35 weeks of gestation may balance the risk of perinatal death with the risks of infant mortality, respiratory distress syndrome, mental retardation, and cerebral palsy related to prematurity. At any given gestational age, incorporating amniocentesis for verification of fetal lung maturity does not improve outcomes.