Is fetal acidemia at the time of scheduled cesarean associated with neonatal morbidity?

Abstract

Fetal acidemia at the time of scheduled cesarean delivery (CD) can be unexpected. In the setting of reassuring preoperative monitoring, the duration of fetal acidemia in this scenario is presumably brief. We assessed whether this brief acidemia is associated with poor neonatal outcomes. This is a retrospective cohort study of women delivering live, non-anomalous, term singletons via scheduled CD from 2004-2014 at a single tertiary care center with a universal cord gas policy. Laboring women and women whose CD was performed for non-reassuring fetal status were excluded. The primary outcome was composite neonatal morbidity (neonatal death, hypoxic-ischemic encephalopathy, therapeutic hypothermia, intubation, respiratory distress syndrome, or seizures). This outcome was compared between patients with and without acidemia (umbilical artery [UA] pH < 7.20). Multivariable logistic regression was used to adjust for confounders. Secondary analyses using pH cut-offs of 7.10 and 7.00 were also performed. Of 2081 pregnancies undergoing scheduled CD, 252 (12.1%) had fetal acidemia at time of delivery. Acidemia was more common in breech and macrosomic fetuses and fetuses born to women with obesity and gestational diabetes. Fetal acidemia at time of scheduled CD was significantly associated with neonatal morbidity (aOR 3.89, 95% CI 2.31-6.54). This effect was not modified by an elevated UA lactate. (p-value for interaction 0.88). The risk of neonatal morbidity significantly increased as UA pH decreased (Figure). After controlling for confounders, fetal acidemia at all pH cut-offs remained significantly associated with neonatal morbidity (Table). Even a presumably brief period of mild acidemia is associated with neonatal morbidity at the time of scheduled CD despite reassuring preoperative monitoring. Addressing intraoperative factors that contribute to fetal acidemia at time of scheduled CD is an important priority.View Large Image Figure ViewerDownload Hi-res image Download (PPT)