Factors associated with umbilical arterial blood pH in term neonates delivered via cesarean section: A retrospective cohort study

ObjectiveThis retrospective cohort study aimed to identify perinatal factors associated with umbilical arterial pH in term neonates delivered via cesarean section, using a pH cutoff of 7.20 to define neonatal acidosis.MethodsWe analyzed clinical data from 356 mother-neonate dyads who underwent cesarean delivery at a tertiary hospital between January 2020 and December 2022. Neonates were categorized into two groups based on umbilical arterial pH values (<7.20 vs. ≥7.20). We evaluated maternal and intrapartum factors, including amniotic fluid quality (operationally defined as clear or meconium-stained (grades I-III)), duration of labor, and fetal distress. Statistical analyses included multivariable logistic regression to quantify associations (reported as odds ratios with 95% confidence intervals) and random forest modeling to identify key predictors. Model performance was assessed via receiver operating characteristic curve analysis.ResultsThe incidence of acidosis (umbilical arterial pH <7.20) was 51.0% (52/102). Meconium-stained amniotic fluid (adjusted odds ratio: 3.12; 95% confidence interval: 1.75-5.58; p < 0.001) and trial of labor (adjusted odds ratio: 2.45; 95% confidence interval: 1.40-4.30; p = 0.002) were significantly associated with acidosis. The random forest model identified these factors as the top predictors, with an area under the curve of 0.71 (95% confidence interval: 0.68-0.74) based on 10-fold cross-validation.ConclusionMeconium-stained amniotic fluid and prolonged labor are strongly associated with acidosis in term cesarean deliveries. Early identification of these factors may aid in risk stratification and perinatal management.