No Link Between Maternal Health During Pregnancy and Autism, Researchers Say

A mom’s health during pregnancy is not likely to influence her child’s risk of autism, a new study argues.

Many previous studies have reported such a link, but researchers say nearly all these associations can be explained by other autism risk factors — genetics, pollution exposure, access to health care and the like.

“Our study shows that there is no convincing evidence that any of these other diagnoses in the mother can cause autism,” senior researcher Magdalena Janecka, an associate professor of child and adolescent psychiatry at NYU Grossman School of Medicine in New York City, said in a news release.

“Many mothers of children with autism feel guilty about it, thinking that they did something wrong during pregnancy, and it is heartbreaking,” Janecka said. “I think showing that these things are not going to cause autism is important and may lead to more effective ways to support autistic children and their families.”

For the study, researchers analyzed more than 1.1 million pregnancies among 600,000 mothers listed in a national registry in Denmark.

The team used medical records to check each woman for more than 1,700 distinct diagnoses.

They then corrected for health factors that could offer an alternative explanation for the purported link between a pregnant woman’s health and her child’s autism.

“We believe our study is the first to comprehensively examine the entire medical history of the mother and explore a wide range of possible associations, controlling for multiple concurrent conditions and confounding factors,” lead researcher Dr. Vahe Khachadourian, a research assistant professor at NYU Grossman School of Medicine, said in a news release.

After accounting for these confounding factors, the team found that 30 diagnoses among mothers were still statistically associated with autism in children. For example, it appeared as though diabetes increased autism risk by 19%, and depression by 49%.

But researchers then compared children with autism to their siblings, to test if these health problems in mom happened alongside autism rather that causing it.

If a mom had the same health problems during pregnancies of children with and without autism, that would suggest factors other than her illness were influencing her child’s risk of autism, researchers reasoned.

For example, genetics related to depression are closely tied to those of autism, researchers noted. A woman suffering depression during pregnancy likely shares genes with her child that cause both depression and autism, rather than depression somehow affecting the fetus and causing autism.

After accounting for such familial factors, the only maternal diagnosis still associated with autism was pregnancy complications related to the fetus, researchers found.

“Our interpretation is that these fetal diagnoses likely do not cause autism, but are instead early signs of it,” Janecka said.

However, researchers noted that their findings should be tested in other groups of people, to verify that a mom’s health does not influence autism risk.

The new study appears in the journal Nature Medicine.

More information

The Autism Research Institute has more on autism.

SOURCE: NYU Langone Health, news release, Jan. 31, 2025

Source: HealthDay