Intraparturn epidural analgesia and maternal temperature regulation

OBJECTIVE: To examine maternal temperature changes after epidural analgesia. METHODS: A prospective cohort of nulliparas at term was monitored with hourly maternal tympanic temperatures after epidural analgesia (n=99). Temperature response after epidural analgesia was examined in the group as a whole. Subsequently, mean maternal temperature curves were compared between women who remained afebrile throughout labor (n=77) and women who developed intrapartum fever with body temperature greater than 100.4'F (n=22). Baseline maternal characteristics were assessed. RESULTS: Women who later developed intraparturn fever had a higher mean temperature within 1 hour after epidural analgesia. In contrast, women who remained afebrile had no increase in core temperature. During the first 4 hours after epidural analgesia initiation, women who later develop intraparturn fever have an increase in mean tympanic temperature of 0.33oF per hour. CONCLUSION: Epidural analgesia is not associated with increased temperature in the majority of women. Hyperthermia is an abnormal response confined to a minority subset, which occurs immediately after exposure. Our findings do not support a universal perturbation of maternal thermoregulation after epidural analgesia.