Epidural Analgesia Linked to Major Reduction in Severe Maternal Morbidity

Originally published by our sister publication Anesthesiology News

The use of epidural analgesia during labor was associated with a 35% reduction in cases of severe maternal morbidity (SMM), particularly in women with medical indications for an epidural and those with preterm births, according to the results of a study conducted in the United Kingdom.

The findings indicate a need for further research into alternative analgesic approaches in women who may require more aggressive management, as well as attention to multimodal pain treatment strategies, the researchers said (BMJ 2024;385:e077190).

“Our findings were in keeping with our clinical experience and observations that the higher the level of underlying risk for an adverse outcome, the more a woman might have to gain from having epidural analgesia in labor,” said lead researcher Rachel J. Kearns, MD, a consultant anesthesiologist at the Glasgow Royal Infirmary and the School of Medicine at the University of Glasgow, in Scotland. “We found that having an epidural during labor can significantly reduce health complications for mothers during childbirth and the weeks after.”

Epidural Analgesia Prevented Some Cases of SMM

Among the 567,216 women included in the study, 125,024 (22%) received epidural analgesia during labor and 2,412 developed SMM (4.3/1,000 births; 95% CI, 4.1-4.4). Epidural analgesia was associated with statistically significant reductions in rates of both SMM (adjusted relative risk [ARR], 0.65; 95% CI, 0.50-0.85) and SMM plus critical care admission (ARR, 0.46; 95% CI, 0.29-0.73).

Findings

The researchers reported some findings that are difficult to fully explain. For instance:

• Greater risk reductions in SMM were observed in women with a medical indication for epidural analgesia (ARR, 0.50; 95% CI, 0.34-0.72) versus those with no such indication (ARR, 0.67; 95% CI, 0.43-1.03; P<0.001).
• Greater reductions in SMM were reported in women delivering preterm who received an epidural (ARR, 0.53; 95% CI, 0.37-0.76) compared with those delivering at term or after term (ARR, 1.09; 95% CI, 0.98-1.21; P<0.001).
• They also noted that “the observed reduced risk of SMM with epidural analgesia was increasingly noticeable as gestational age at birth decreased in the whole cohort, and in women with a medical indication for epidural analgesia.”

These variations in SMM rates could not be fully explained by the known effects of epidural analgesia.

How Might Epidural Analgesia Influence SMM Rates?

The authors suggested potential mechanisms by which epidural analgesia could influence SMM:

• Adherent medical oversight and hemodynamic monitoring are standard practices during epidural administration.
• An epidural is often accompanied by IV access and fluid administration.
• Efforts are made to blunt the physiologic stress responses to labor, allowing for more focused clinical attention on the patient.
• Efforts are made to avoid the need for spinal or general anesthesia or cesarean delivery.
• The increased attention that accompanies an epidural may result in faster escalation to definitive obstetric interventions in emergent conditions.

“Using epidural analgesia during labor alters the care pathway to one that enhances the capacity to manage adverse events,” the authors concluded. “From these data it is not possible to separate the direct influence of epidural analgesia from the accompanying comprehensive care package.”

In an editorial accompanying the study (BMJ 2024;385:q1053), Sarah V. Devroe, MD, wrote that Kearns and colleagues had identified “a notable positive association, with epidural analgesia linked to a 35% reduction in SMM. This important benefit was particularly noticeable among women with a medical indication for epidural analgesia during labor and those undergoing preterm birth. The implications of these findings for obstetric anesthetic practice and maternal health warrant careful consideration and further exploration.

“Kearns’ findings could lead to efforts to improve equitable access to epidurals, potentially reducing severe maternal morbidity and enhancing health outcomes across various socioeconomic and ethnic backgrounds,” Devroe, a consultant anesthesiologist at UZ Leuven, Group Biomedical Sciences, in Belgium, told Anesthesiology News. “I hope this study reduces the controversy around labor epidurals, which are sometimes seen as “medicalizing” childbirth. Epidurals effectively manage labor pain, similar to other medical innovations.”

By John Henry Dreyfuss

Devroe and Kearns reported no relevant financial disclosures.