Maternal serum C-reactive protein and white blood cell count at hospital admission as predictors of intrapartum maternal fever: a retrospective case-control study in women having epidural labor analgesia

Non-infectious inflammation has been proposed as a major contributor to epidural-related maternal fever. We hypothesized that maternal serum C-reactive protein (CRP) and white blood cell (WBC) count at hospital admission predict intrapartum maternal fever.A retrospective case-control study of low-risk women admitted for vaginal deliveries at a tertiary hospital in 2019. Women with a singleton pregnancy at term and a cephalic presentation who received epidural labor analgesia and developed intrapartum fever (≥38.0°C) were included. Controls matched by parity and gestational age received epidural analgesia without fever. The associations of maternal CRP level and WBC count on admission with fever were evaluated by a multivariable logistic regression analysis. The predictive performances of both markers for fever were evaluated by receiver-operating characteristic (ROC) curves.Overall, 687 women met the inclusion criteria and 687 served as controls. The WBC count on admission was higher in febrile than in afebrile women (8.7 vs. 8.5 × 109/L, P=0.001) and was moderately associated with fever (women within the highest quartile vs. the lowest quartile, adjusted odds ratio 1.92; 95% confidence interval [CI] 1.34 to 2.75), but the predictive performance for fever was low (area under the ROC curve 0.55, 95% CI 0.52 to 0.58). Admission CRP values were not associated with fever. When stratified by labor status on admission, the association of WBC count with fever was only in non-laboring women.Maternal serum CRP and WBC at hospital admission do not predict intrapartum fever in women having epidural labor analgesia at term.