Epidural anesthesia administered during labor does not increase the risk for autism in children

April 26, 2021

Having an epidural during childbirth is not associated with a greater risk of autism in the child, according to a study led by researchers at the Stanford University School of Medicine and the University of Manitoba, according to a news release from Stanford.

The study, which was published online April 19 in JAMA Pediatrics, helps resolve questions raised by an earlier, widely criticized report on the topic.

In October 2020, a study of California births said epidural use was associated with a 37% greater risk of later autism diagnosis for children. But the study was widely criticized for failing to account for many socioeconomic, genetic and medical risk factors for autism – separate from the epidural – that could be more common among women who choose epidurals.

The new research examined epidural use during childbirth and later diagnoses of autism in Manitoba, Canada. It included 123,175 children who were born between 2005 and 2016 and were followed until 2019.

All of the children in the study were born via vaginal delivery and were single births – not twins or other multiples. Of those studied, 38.2% of the children were exposed to epidural anesthesia during labor; the rest were not. Of children exposed to epidurals during labor, 2.1% were later diagnosed with autism spectrum disorder, compared with 1.7% of children not exposed to epidurals.

But then the researchers controlled for factors thought to potentially influence autism risk – many more such factors than in the prior study. Those included socioeconomic factors (mothers’ education, marital status, neighborhood socioeconomic level and receipt of welfare during pregnancy); mothers’ pre-pregnancy medical history (including diabetes, hypertension, anxiety and depression); medical conditions during pregnancy; mothers’ smoking, alcohol and recreational drug use; mothers’ hospitalization for mental illness during pregnancy; mothers’ use of several types of prescription medications (benzodiazepines, antidepressants and antiepileptics); medical complications of delivery; and factors related to the mothers’ pregnancy and labor, including the length of the pregnancy, whether labor was induced or augmented, and whether the fetus was large or in distress during labor.

The researchers also analyzed pairs of siblings in which the mother received an epidural during one child’s birth but not the other. This comparison gave a way to account for genetic and familial factors, which influence autism risk.

Once the researchers had adjusted for all the confounding factors, there was no statistically significant difference in autism risk between children whose mothers received epidurals during their birth and those who did not. Accounting for genetic and family-related factors reduced the difference between the groups even more.

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