Epidural in Labor and Delivery Not Tied to Autism Risk, Two Studies Suggest

By Lisa Rapaport

September 29, 2021

(Reuters Health) - Women who use epidural analgesia during labor and delivery may be no more likely than those who don't to have a child with autism spectrum disorder, two new studies published in JAMA suggest.

One study examined data on 388,254 children born in British Columbia, Canada between April 1, 2000, and December 31, 2014, including 5,192 (1.34%) children diagnosed with autism and 111,480 (28.7%) who were exposed to epidural analgesia during labor and delivery. This study found a slight increased risk for autism with epidural exposure (adjusted hazard ratio 1.09) but concluded it was likely due to residual confounding.

The other study examined data on 479,178 children born in Denmark between January 2006 and December 2013, including 6,428 (1.3%) who were diagnosed with autism and 92,900 (19.4%) who had epidural exposure during labor and delivery. This study found epidural exposure wasn't significantly associated with autism risk (aHR 1.05).

"Current evidence does not suggest that use of labor epidurals increases the risk of autism spectrum disorder," said Dr. Cynthia Wong, professor, chair and department executive officer for analgesia at University of Iowa Healthcare and the Carver College of Medicine in Iowa City and co-author of an editorial accompanying the studies.

"Therefore, this risk does not need to be considered when advising women about pain management during labor," Dr. Wong said by email.

In the Canadian study, 1.53% of children exposed to epidural analgesia received a diagnosis of autism spectrum disorder (ASD), compared with 1.26% of children without this exposure. The study adjusted for sociodemographics, maternal conditions, risk factors during pregnancy, labor and delivery circumstances, and neonatal characteristics.

When researchers did a within-mother matched analysis, they found no significant association between epidural use during labor and delivery and autism in offspring.

"This matched analysis controls for other important factors that are likely to remain constant within a woman over time - e.g. genetics, propensity to use medical care, etc.," said lead study author Gillian Hanley of Vancouver General Hospital.

"The null finding in this analysis further suggests that the positive association in the main cohort was a result of residual confounding and not actually representative of a significant association between epidural analgesia and ASD," Hanley said by email.

In the Danish study, children exposed to epidural analgesia during labor and delivery had an autism incidence rate of 23.1 per 10,000 person years, compared with 18.5 cases per 10,000 person-years among children without this exposure.

This Danish study adjusted for many of the same factors used in the Canadian study, said lead author Dr. Anders Pretzmann Mikkelsen of the department of obstetrics and gynecology at Copenhagen University Hospital-Rigshospitalet in Denmark.

However, the Danish study also accounted for several potential confounders not examined in the Canadian study including maternal history of psychiatric disease, psychotropic medication, and family history of autism, Dr. Mikkelsen said by email.

"The similarities between the results of the two studies are quite striking," Dr. Mikkelsen said. "Where our studies differ slightly, is in adjusting for confounders."

Taken together, both studies should reassure clinicians that epidural analgesia isn't significantly associated with a risk for autism, Dr. Mikkelsen concluded.

"My personal opinion based on current evidence is if a labor epidural is indicated during delivery, clinicians should not hesitate to offer it to patients due to concerns that it could cause autism in children," Dr. Mikkelsen said.

SOURCE: https://bit.ly/3okhNES, https://bit.ly/3kP0v0p and https://bit.ly/3CVt7eU JAMA, online September 28, 2021.