A randomized trial of the effects of antibiotic prophylaxis on epidural-related fever in labor.

Background: It has been suggested that the development of maternal fever during epidural analgesia could be due to intrapartum infection. We investigated whether antibiotic prophylaxis before epidural placement decreases the rate of epidural-related fever.

Methods: In this double-blind, placebo-controlled trial, 400 healthy nulliparous women requesting epidural analgesia were randomly assigned to receive either cefoxitin 2 g or placebo immediately preceding initiation of epidural labor analgesia. Maternal tympanic temperature was measured hourly, and intrapartum fever was defined as a maternal temperature of ≥38°C. Neonates born to women with fever were evaluated for possible sepsis, and available placentas were evaluated for the presence of neutrophilic inflammation. The primary outcome was maternal fever during epidural analgesia.

Results: Thirty-eight percent of women in the cefoxitin group and 40% of women in the placebo group developed fever (P = 0.68). The risk difference (95% confidence interval) for fever ≥38°C during labor (antibiotic versus placebo) was -2.0% (-11.5 to 7.5), and for fever >39°C during labor was -1.5% (-4.7 to 1.7). Approximately half of each study group had placental neutrophilic inflammation, but administration of cefoxitin had no significant effect on any grade of neutrophilic inflammation. Fever developed significantly more often in the women with placental neutrophilic inflammation compared with those without such inflammation (73/158 vs 33/144, P < 0.001; risk difference 23% [95% confidence interval, 13.0-34.0]). There were no significant differences in any neonatal outcomes between the antibiotic and placebo study groups. Sepsis was not diagnosed in any of the infants. There were no neonatal deaths.

Conclusion: Fever during labor epidural analgesia is associated with placental inflammation, but fever and placental inflammation were not reduced with antibiotic prophylaxis. This finding suggests that infection is unlikely to be the cause in its development.