OBJECTIVETo determine if women receiving continuous epidural analgesia are more likely to develop intrapartum fever and related neonatal effects.METHODSWe conducted a retrospective cohort analysis of nulliparous women with term gestations in spontaneous labor delivered during a 12-month period immediately before the availability of on-demand labor epidural analgesia (Before group) and a similar group of nulliparas delivered after labor epidural analgesia was available on request (After group).RESULTSThe frequency of epidural increased from 1% before the availability of on-request epidural analgesia to 83% after epidural analgesia was available on request. A maximal temperature of at least 100.4F was detected in three of 498 (0.6%) women in the Before group, and in 63 of 572 women (11.0%) in the After group (relative risk [RR] = 18.3, 95% confidence interval [CI] 5.8, 57.8,P< .01). Logistic regression analysis demonstrated that on-request labor epidural analgesia was associated with an intrapartum temperature of at least 99.5F (RR = 3.0, 95% CI 2.3, 3.6,P< .001) and intrapartum temperature of at least 100.4F (RR = 20.2, 95% CI 7.0, 86.0,P< .001). There were statistically significant increases in the proportion of newborns who had complete blood counts (24% versus 13.5%, RR = 1.5, 95% CI 1.3, 1.8,P< .01) and blood cultures (30.7% versus 8.6%, RR = 1.7, 95% CI 1.2, 2.4,P< .05) in the After period compared with the Before group; however, there was no statistically significant difference in the proportion of infants who received antibiotic therapy for presumed sepsis between the After and Before periods (5.8% versus 4.6%, RR = 1.15, 95% CI 0.8, 1.6,P= .38). No infants in either group had culture-proven sepsis.CONCLUSIONThe use of labor epidural analgesia is associated with a clinically significant increase in the incidence of intrapartum fever.