A comparative study of neonatal outcomes in placenta previa versus cesarean for other indication at term

Currently, no ACOG guidelines address the issue of the optimal timing of delivery in placenta previa. Though there is an increased risk of neonatal morbidity and mortality when electively delivered preterm, it is unclear whether adverse neonatal outcomes exist when these pregnancies make it beyond term. By comparing neonatal outcomes amongst pregnancies with placenta previa versus those from cesarean for another indication at term, the objective of this study was to determine whether placenta previa is an independent risk factor for adverse neonatal outcomes at term.

We conducted a population-based cohort-study using the CDC's Linked Birth-Infant Death data from the United States. The effect of placenta previa on the risk of adverse neonatal outcomes was estimated using unconditional logistic regression analysis, adjusting for relevant confounders.

Our cohort consisted of 3,550,842 deliveries meeting inclusion criteria. The incidence of placenta previa at term was 1.3/1000 (n = 4,492), accounting for 40.6% of all previa cases. Relative to cesareans for other indications, pregnancies with placenta previa had an increased risk of IUGR 3.20 [2.50-4.10], SGA 2.70 [2.45-2.97], respiratory distress 3.82 [2.91-5.00], prolonged ventilation 3.41 [2.70-4.32] and neonatal anemia 6.87 [4.43-10.65]. Rates of meconium aspiration syndrome, seizures, birth injury and overall infant mortality do not appear to be affected by this condition.

Relative to cesareans for other indications, placenta previa is associated with increased morbidity, but not mortality, at term. This information might be helpful in the development of future guidelines, which are currently needed to guide and standardize clinical practice regarding the optimal timing of delivery in placenta previa.