Objective: To assess whether epidural analgesia is associated with fever, i
ndependent of maternal infection, by evaluating the relationship between ep
idural analgesia and inflammation of the placenta.
Methods: Placentas collected prospectively from women with singleton gestat
ions, who delivered 6 hours or more after membrane rupture, were evaluated
systematically for histologic inflammation by an investigator blinded to al
l clinical information. Maternal and neonatal markers of infection were ass
essed in the cohorts who did and did not receive epidural analgesia.
Results: One hundred forty-nine consecutive placentas were analyzed, and 80
(54%) of these women received epidural analgesia. On univariate analysis,
significant differences between epidural and no epidural groups were found
with respect to maternal fever 38C or greater (46% versus 26%, P = .01), pl
acenta inflammation (61% versus 36%, P = .002), and length of labor (11.8 h
ours versus 9.6 hours, P = .03). The combination of maternal fever plus pla
cental inflammation was significantly more common in the epidural group (35
% versus 17% P = .02). However, maternal fever in the absence of supporting
evidence of infection, in the form of placental inflammation, was not incr
eased after epidural analgesia (11% versus 9%, P = .61).
Conclusion: Epidural analgesia is associated with intrapartum fever, but on
ly in the presence of placental inflammation. This suggests that the fever
reported with epidural analgesia is due to infection rather than the analge
sia itself. (C) 1999 by The American College of Obstetricians and Gynecolog
ists.