A mother’s health during pregnancy is unlikely to influence her child’s risk of autism, according to a new study that challenges previous research suggesting such a connection.

While earlier studies have linked maternal health conditions to autism, researchers argue that most of these associations can be explained by other factors, such as genetics, pollution exposure, and access to healthcare.

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

The findings could offer reassurance to mothers who may feel guilt over their child’s autism diagnosis. “Many mothers of children with autism feel guilty, thinking that they did something wrong during pregnancy, and it is heartbreaking,” Janecka added. “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.”

The study, conducted using Denmark’s national registry, analyzed over 1.1 million pregnancies among 600,000 mothers. Researchers examined medical records to check for more than 1,700 different maternal health conditions and then adjusted for potential confounding factors that could have influenced past findings.

“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,” said lead researcher Dr. Vahe Khachadourian, a research assistant professor at NYU Grossman School of Medicine.

The research offers a fresh perspective on autism risk factors, reinforcing the need to focus on genetic and environmental influences rather than maternal health conditions during pregnancy.