670 Neonatal outcomes after cesarean for non-reassuring fetal status in the first stage of labor

Abstract

Non-reassuring fetal status (NRFS) is the second most common indication for cesarean delivery (CD) accounting for 1 in 4 cesareans. We sought to evaluate neonatal outcomes following CD for NRFS. This was a secondary analysis of a prospective cohort study. We included singleton term pregnancies admitted for labor or induction of labor between 2010-2014. The primary outcome was fetal acidemia defined as umbilical artery (UA) pH < 7.1. Secondary outcomes were UA base excess, lactate, and neonatal composite morbidity (hypoxic-ischemic encephalopathy, meconium aspiration syndrome, hypothermia treatment, intubation, mechanical ventilation, neonatal seizure, death). The exposure was first stage CD for any indication that included NRFS and the control group was all other deliveries. Multivariable logistic regression and the Zhang method was used to estimate relative risk and adjust for confounders. We also performed a sensitivity analysis of patients who underwent CD for the sole indication of NRFS. Of the 8580 patients in the cohort, 721 (8.4%) had a first stage CD for NRFS. Among these, 476 (66.0%) were for the sole indication of NRFS. The risk of fetal acidemia was 5 times higher among patients undergoing CD for NRFS compared to all other deliveries (7.3% vs 1.2%, aRR 5.45[95% CI 3.35-8.68]). UA base excess and lactate were higher among patients with CD for NRFS. CD for NRFS was associated with an increased risk of composite neonatal morbidity (4.0% vs 1.0%, aRR 2.52 [95% CI 1.30-4.78]). After restricting the analysis to patients who had CD for the sole indication of NRFS, the risk of fetal acidemia and neonatal morbidity remained significantly higher in the CD for NRFS group than control deliveries. CD for NRFS is associated with an increased risk of fetal acidemia and composite neonatal morbidity. Although the vast majority of infants delivered for NRFS have normal outcomes, these results suggest that the diagnosis of NRFS using continuous fetal monitoring in labor is predictive of adverse outcomes.