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.

ABSTRACT

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: Maternal serum CRP and WBC at hospital admission do not predict intrapartum fever in women having epidural labor analgesia at term.