Epidural Analgesia and Maternal Fever During Labor

Epidural related maternal fever (ERMF) refers to the phenomenon of increased body temperature of parturient after receiving epidural analgesia during labor. Women who receive epidural labor analgesia are more likely to have fever than those who do not. In a systematic review, 20-33% of parturients receiving neuraxial analgesia developed fever during labor, compared with only 5-7% of those without neuraxial analgesia. Maternal fever can interfere with women's laboring process, decrease the sensitivity of the uterus and cervix to oxytocin, and lead to dystocia and increased surgical delivery rate. The investigators note that the rate of ERMF is lower in patients receiving lower density neuraxial blockade. The study is designed to test the hypothesis that the effect of epidural analgesia is associated with the development of maternal fever, i.e., better analgesia is associated with higher risk of maternal fever.

Inclusion criteria

• Age ≥18 years old;
• Nulliparae with single term cephalic pregnancy;
• Preparing to give vaginal delivery under epidural analgesia.

Exclusion criteria

• Basal body temperature ≥37.3°C;
• Presence of serious pregnancy complications (such as severe preeclampsia, placenta accreta, HELLP [Hemolysis, Elevated Liver enzymes, Low Platelet count] syndrome, placenta previa, abruption of placenta, or hyperthyroidism);
• History of hyperthyrodism, including hyperthyrodism in pregnancy;
• Taking sedatives and/or analgesics within one week before planned delivery;
• American Society of Anesthesiologists classification >class III;
• Contraindications to epidural puncture, including central nervous system diseases (such as poliomyelitis), spinal diseases (such as intraspinal mass, lumbar disc herniation, history of spinal trauma, etc.), abnormal blood coagulation, etc.;
• Presence of infections, including obstetric infections, systemic infections (such as sepsis, bacteremia), or infections at the puncture site or adjacent sites;
• Other conditions that are considered unsuitable for study participation;
• Refused to participate in the study.