Risk factors of maternal intrapartum fever and the effect of fever duration on neonatal morbidity in different temperature

Aim: To investigate the clinical risk factors of intrapartum fever and explore the relationship between fever duration and neonatal morbidity of different fever peak.

Methods: A case-control study was conducted, and 714 pregnant women were divided into fever and nonfever group. Multivariable logistic regression model was estimated to evaluate the risk factors for maternal intrapartum fever. Receiver operating characteristic curve was adopted to explore the relationship between fever duration and fetal distress of different fever peak to find the cut-off point, then the neonatal outcomes of women with fever ≥38°C in two groups of different fever duration were compared.

Results: Epidural analgesia (odds ratio [OR]: 6.89, p < 0.001), longer time of membrane rupture (OR: 1.06, p < 0.001) and longer time of first stage of labor (OR: 1.04, p = 0.03) were considered as independent risk factors for maternal fever. For women with temperature <38°C, fever duration was not associated with fetal distress, whereas the women with temperature ≥38°C, fever duration longer than 93.5 min was a good predictor of fetal distress (Area under curve (AUC) = 0.82, p < 0.05). Further analysis showed that infants of women with fever peak ≥38°C and fever duration longer than 90 min had a higher rate of 1 min Apgar score <7 (15.5% vs. 2.2%, p = 0.03), assisted ventilation (29.6% vs. 11.1%, p = 0.02), and admission to neonatal ward (87.3% vs. 60.0%, p = 0.001).

Conclusions: Epidural analgesia, longer time of membrane rupture, and longer time of first stage of labor were considered as independent risk factors for maternal intrapartum fever. For women with fever ≥38°C, controlling fever time less than 90 min might be helpful to reduce neonatal morbidity.