Predictors of adverse neonatal outcome in pregnancies complicated by placenta previa

We aimed to underline the determinants of adverse neonatal outcome in gestations complicated by placenta previa (PP).

A retrospective study including all women diagnosed with placenta previa carrying a singleton gestation who delivered between 2011 and June 2019. Gestations with adverse neonatal outcomes were compared to those without. In a secondary analysis, we further studied the rate of Placenta accreta spectrum (PAS) in relation to number of previous cesarean deliveries.

Overall, 548/84,558 (0.6%) singleton deliveries were complicated by PP (0.6%). PAS was noted in 105 (19.2%) cases. After exclusion of PAS cases, adverse neonatal outcome occurred in 149/443 (33.6%), median gestational age of delivery was 37 ^0/7 with a median birthweight of 2780 g. In a univariate analysis, adverse neonatal outcome was associated with emergent delivery and general anesthesia [56.8% vs. 20.8%, OR 5.00 (95% CI) 3.24-7.72, p < 0.001 and 54.4% vs. 24.8%, OR 3.60 (95% CI) 2.37-5.47, p < 0.001, respectively]. Gestational age at delivery was lower in the adverse outcome group (mean 35 ^1/7 vs. 37 ^3/7, p < 0.001). In a multivariate regression analysis, general anesthesia and gestational age at delivery were independently associated with adverse neonatal outcome [adjusted odds ratio (aOR) 2.26 (95% CI) 1.18-4.31, p = 0.01, aOR 1.10 (95% CI) 1.05-1.16, p < 0.001. Analysis of the rate of PAS among women with previous cesarean delivery and PP revealed that no cases of PAS were noted when no prior cesarean delivery was present. The rate of PAS for previous 1, 2, 3, 4 and 5 cesarean deliveries was 26.7%, 43.5%, 65.5%, 55.6% and 66.7% respectively.

Efforts should be made to avoid general anesthesia in deliveries of PP.