Factors associated with epidural-related maternal fever in low-risk term women: a systematic review

Background The underlying mechanism of epidural-related maternal fever (ERMF) is not fully understood. This systematic review aimed to identify factors associated with ERMF in low-risk, full-term women using neuraxial analgesia. Methods PubMed, Embase, Web of Science, CENTRAL, and Wanfang Data were searched from inception to September 10, 2022 with no language restriction. Studies reported descriptive data regarding the factors associated with ERMF. A random effects model meta-analysis was used to pool the raw data of univariate analyses for each identified factor. Sensitivity and subgroup analyses were performed to explore possible sources of heterogeneity. Results Eighteen observational studies involving 33 427 women were included, with 18 factors eligible for meta-analyses. Higher body mass index, baseline temperature, admission maternal interleukin-6 levels and white blood cell counts, nulliparity, increasing gestational age, longer duration of labor and rupture of membranes, increasing number of vaginal examinations, oxytocin use, higher birth weight, lower cervical dilation at initiation of analgesia, and longer analgesia duration were associated with increased risk of ERMF, while intermittent compared with continuous epidural dosing was associated with a decreased risk of ERMF (odds ratio 0.25, 95% CI 0.16 to 0.48, P < 0.001). However, heterogeneity among studies was high and the quality of evidence was low for these meta-analyses, except for intermittent epidural dosing. Conclusions Many factors are associated with ERMF but may not be independent or causal. Further study is needed to clarify the interactions of these factors in ERMF development and whether modification of these factors might influence risk of ERMF.