Decision analysis suggests that planned delivery at 34 weeks yields optimal outcomes for women with placenta previa and accreta. Abnormal placentation is associated with excess risk for maternal hemorrhage, urgent delivery, and preterm birth. Sometimes imaging can be useful for antenatal diagnosis of placenta accreta; nonetheless, optimal delivery timing for women with placenta previa and accreta is controversial, and prospective trials are unlikely to be conducted. Investigators at Northwestern University used a decision-analytic approach to model outcomes associated with planned deliveries at gestational ages ranging from 34 to 39 weeks with varied management options (e.g., antenatal glucocorticoid administration, evaluation of fetal lung maturity). Using published estimates of likelihood of adverse occurrences, such as neonatal respiratory distress, infant death, and maternal ICU admission, the primary outcome of quality-adjusted life years (QALYs) was modeled for nine possible management strategies. The highest QALY ranking for both mother and child was associated with scheduled delivery at 34 weeks, 1 week after administration of antenatal corticosteroids. Number of QALYs fell incrementally with planned delivery at each subsequent week, and at no given gestational age was waiting for documented lung maturity associated with a better outcome than was "outright" delivery. These outcome rankings held true for all instances in which the estimated risk for antenatal hemorrhage was 11%.— Allison Bryant, MD, MPH
Placenta accreta is defined as the deep attachment of the placenta in the uterine wall. One major risk when a mother has placenta accreta is bleeding due to manual attempts to separate the placenta from the uterine wall. To prevent this, the baby must be delivered before reaching 40th week. The question now is when? One factor...