694 Impact of neonatal birth weight on adverse perinatal outcomes in cesarean deliveries in nulliparous women

Abstract

To investigate the association between neonatal birth weight (NBW) and adverse perinatal outcomes in nulliparous cesarean deliveries (CD). This is a retrospective cohort study of singleton, non-anomalous, term CD of nulliparous women 2007-2011 using linked vital statistics and ICD-9 data. Neonatal adverse outcomes examined included brachial plexus injury (BPI), clavicular fracture (CVF), neonatal intensive care unit (NICU) admission, hypoxic-ischemic encephalopathy (HIE), hypoglycemia (HG), and a composite of severe neonatal outcomes (including neonatal seizure, APGAR score ≤3, and neonatal death). Maternal adverse outcomes examined included postpartum hemorrhage (PPH) and maternal blood transfusion (MBT). Chi-square tests were used to compare rates of perinatal adverse outcomes for births in varying neonatal birth weight categories. Multivariable logistic regression was used to control for maternal BMI, diabetes, race/ethnicity, age, education, insurance, parity, and prenatal care. In a cohort of 258,490 CD, we found significantly higher rates of neonatal adverse outcomes, including BPI, CVF, NICU admission, and HG, with rising NBW (Figure 1). Risk of BPI and CVF rose from 0.01% in 3000-3400 neonates to 0.06% and 0.08%, respectively, in neonates ≥4500g (p=0.003). Risk of HG increased from 0.6% in 3000-3400g neonates to 3.7% in neonates ≥4500g (p<0.001). Regarding maternal outcomes, the risk of PPH and MBT rose from 1.8% and 1.1%, respectively, in 3000-3499g neonates, to 4.8% and 2.1%, respectively, in neonates ≥4500g (p<0.001). After controlling for potential confounders, there remains a statistically significant increase in odds of PPH and MBT across all NBW categories when compared with 3000-3499g neonates (Table 1). A statistically significant increase in odds of HG was also noted for 4000-4499g and ≥4500g when compared with 3000-3499g neonates. Higher NBW increases the risk of perinatal complications in the setting of nulliparous CD. Providers should exercise heightened awareness of the effect of NBW on these potential adverse outcomes when managing CD.View Large Image Figure ViewerDownload Hi-res image Download (PPT)