Objective: To determine whether the reported association of maternal fever with neonatal encephalopathy is independent of other associated intrapartum risk factors.
Design: Prospective cohort study.
Setting: Dublin teaching hospital delivery ward.
Population: 4,915 low risk women in labour at 36-41 weeks of gestation.
Methods: Using logistic regression with odds ratios and 95% confidence intervals, the incidence of neonatal encephalopathy and other neonatal outcomes of women who had an intrapartum fever >37.5 degrees C was compared with those who did not.
Results: The cohort comprised 33% of all deliveries during the study period. Neonatal encephalopathy was diagnosed in 3.25/1,000 births. The incidence of intrapartum fever was 6.8%. Maternal fever was strongly associated with neonatal encephalopathy (crude OR 10.8, 95% CI 4.0-29.3). Univariate analysis showed maternal fever was associated with epidural analgesia, nulliparity, induction, longer labour, oxytocin administration, greater fetal birthweight and gestational age and instrumental vaginal delivery, but not with prolonged (>24hours) prelabour rupture of the membranes. The association of fever with neonatal encephalopathy persisted having adjusting for these covariates (adjusted OR 4.72, 95% CI 1.28-17.4).
Conclusions: The relationship between maternal intrapartum fever and neonatal encephalopathy is independent of other known intrapartum risk factors. This provides further evidence for the role of inflammatory processes in the aetiology of neonatal neurological morbidity.