Intrapartum Temperature Elevation, Epidural Use, and Adverse Outcome in Term Infants

Abstract

A number of studies have reported an association between the use of epidural analgesia in labor and the occurrence of intrapartum maternal fever. Studies of term pregnancies have also reported an increase in adverse neonatal outcomes with intrapartum maternal fever. The aim of this retrospective cohort study was to assess the impact of epidural-related temperature elevation on neonatal outcome and to determine whether epidural analgesia is associated with adverse neonatal outcomes without temperature elevation. Participants were low-risk nulliparous women with singleton term pregnancies ≥37 weeks, delivering at a single hospital during 2000. Pregnancies in which infants had documented sepsis, meningitis, or a major congenital anomaly were excluded. In the first phase of this analysis, neonatal outcomes were compared in women receiving (n = 1538) and not receiving epidural analgesia (n = 363) without elevation of intrapartum temperature (≤99.5°F). In the second phase, neonatal outcomes were compared according to the degree of temperature elevation within the group of women receiving epidural (n = 2784). Multiple logistic regression analysis was used to estimate the association of maternal temperature elevation and neonatal outcomes, controlling for confounding variables. During labor, substantially more women receiving epidural (19.2%, 535/2784) developed maternal temperature >100.4°F compared with those not receiving epidural (2.4%, 10/425). No significant differences in adverse neonatal outcomes were found between women receiving and not receiving epidural in the absence of intrapartum temperature elevation (≤99.5°F). There was a significant linear trend among women receiving epidural between maximum maternal temperature and higher risk of all adverse neonatal outcomes examined including hypotonia, need for assisted ventilation, low 1- and 5-minute Apgar scores, and early-onset neonatal seizures. Multiple logistic regression analysis showed that maternal fever >101°F was associated with a 2- to 6.5-times increased risk of all adverse neonatal outcomes. These findings indicate that intrapartum maternal temperature >99.5°F is associated with an increase in adverse neonatal outcomes, with the proportion of affected infants increasing directly with the degree of epidural-related elevated maternal temperature. Epidural use in the absence of temperature elevation is not associated with adverse neonatal outcomes.