A late-preterm, early-term stratified analysis of neonatal outcomes by gestational age in placenta previa: defining the optimal timing for delivery

Abstract

Objective: Though no official guidelines address the issue of the optimal timing of delivery in placenta previa, common practice is to conduct delivery between 36 and 37 weeks gestation. Given the rising concerns regarding unnecessary premature deliveries, the objective of this study was to compare neonatal outcomes among pregnancies complicated by placenta previa delivered at the late-preterm period (35, 36 weeks) relative to the early-term period (37 and 38 weeks).

Methods: We conducted a retrospective, population-based, cohort study using the CDC’s Linked Birth-Infant Death data files from the U.S. for the year 2004. We stratified the cohort according to gestational age and placenta previa status. Using 38 weeks gestation as reference controls, the effect of delivery in a pregnancy with placenta previa at 35, 36 and 37 weeks gestation on the risk of several neonatal outcomes was estimated using logistic regression analysis, adjusting for relevant confounders.

Results: We analyzed a total of 4 118 956 births, of which 5675 (0.1%) met inclusion criteria. Late-preterm delivery was associated with lower birthweight and increased adequacy of care. Relative to neonates born at 38 weeks, birth at 35, 36 and 37 weeks was associated with no greater odds of meconium passage, fetal distress, fetal anemia, neonatal seizures, increased ventilator needs, or infant death at 1 year. However, odds of 5-min APGAR scores <7 were greater at 35 and 36 weeks (aOR [95% CI]): 3.33 [1.71-6.47] and 2.17 [1.11-4.22], respectively; as were odds of NICU admission rates: 2.25 [2.01-2.50] and 1.57 [1.38-1.76], respectively. Conclusions: Barring maternal indications, early-term delivery in placenta previa is associated with fewer complications and no greater risk than late-preterm delivery. This information may be helpful in the development of future guidelines, which are currently needed to guide the management of these pregnancies.