Is Epidural Analgesia a Predictor of Low Newborn Apgar? A Hospital-Based Observational Study

A painful labor induces adverse maternal effects and increases fetal stress, yet evidence of lack of adverse effect of epidural anesthesia to the newborn Apgar score has been inconsistent. The aim of this study was to investigate maternal, newborn and anesthetic factors associated with a low Apgar score, in particular the effect of modality and timing of epidural analgesia, since this may allow for an appropriate neonatal care planning. We retrospectively analyzed the labor process of 1850 out of 2006 parturients/participants/deliveries at Centro Hospitalar do Porto in 2014. Our primary outcome was newborn Apgar score at fifth minute post-partum. Statistical significance was set as a p value inferior to 0.05. Seventy-one newborns (3.8%) had Apgar score below 7 and 1779 (96.2%) above or equal to 7 at fifth minute. None of the variables identified as maternal age, BMI, previous labor, gestational age, cervix dilation and newborn weight have proved to be different between groups of Apgar below and above 7 (t-test). There was also no significant difference between newborns with Apgar above or below 7 in what concerned initiation of labor, mode of epidural analgesia, previous cesarean, type of delivery and newborn sex (Chi-squared). Median hour of birth and median labor length since beginning of epidural analgesia were not different between the two groups of outcome (Kruskall Wallis). The multivariable model showed that the risk for low Apgar was not independently associated with any of the variables analyzed (Chi-squared Omnibus). In our study, modality and timing of epidural analgesia was not a predictor of low neonate Apgar score at fifth minute postpartum. Nonetheless, we demonstrated that epidural analgesia of low concentration local anesthetics with opioids was non-inferior to the opioid-free variety.