A new study by researchers at the University of Alabama at Birmingham contradicts prior reports that epidural analgesia administered during labor is associated with fever in laboring women.
Women in labor frequently have an increase in body temperature, most often caused by infection but sometimes observed in the absence of any infection.
Previous studies theorized that epidural analgesia is one potential cause for this temperature rise, known as maternal intrapartum fever or MIF. MIF can lead to complications for newborns, including low muscle tone and an increased need for complex resuscitation techniques. It can also lead neonatologists to suspect possible sepsis in newborns, which can mean evaluation and treatment with antibiotics for those newborns.
The UAB study in the August 2012 issue of Anesthesiology indicates that epidural analgesia has no effect on maternal temperature and suggests that long labor and increased body weight are more likely causes for MIF.
“Our primary research focused on studying maternal temperature individually and as a group,” said lead study author Michael Froelich, M.D., associate professor in the Department of Anesthesiology. “We wanted to determine if MIF during labor is a real phenomenon and if it is caused by non-infectious causes.”
Froelich’s team investigated the potential causes of non-infectious MIF changes in 81 laboring women. All but three participants received epidural analgesia. The temperatures in the women prior to receiving epidurals were compared with their temperatures after it was administered.
More than half of participants showed a small positive temperature increase. Findings showed a significant number of women with maternal temperature elevations either had a considerably longer delivery or a higher body-mass index. Epidural analgesia showed no effect on MIF.
“Long labor sustains an inflammatory process that may result in a temperature elevation. Also, the same mechanism may be responsible for patients who are overweight, since the link between obesity and inflammation is well established,” said Froelich.
The study authors believe future research to better identify the exact causes of non-infectious MIF will help identify and treat women who are more prone to fever during labor, including those who experience a longer delivery or have a greater body-mass index.