Study links childhood autism to mothers’ abuse

Abused girls who go on to become mothers are more likely to have children with autism, suggests a new study by researchers at the Harvard School of Public Health.

And women who experienced the most severe physical, emotional, and sexual abuse in childhood are 3.5 times more likely to have children with autism as women who didn’t experience any abuse, according to the study.

While about two percent of women reported the most serious abuse, even women in the top 25 percent of abuse severity – which included mostly women who experienced more moderate levels of abuse – were 60 percent more likely to have a child with autism compared with women who did not experience abuse, according to a news release on the study.

“On the one hand, the very small percentage of women who were exposed to really severe abuse had an enormously higher risk of having a child with autism… but we also wanted to indicate that it wasn’t just a small number of women who were affected,” says lead researcher Andrea Roberts, Ph.D. “It was actually a large number of women who were exposed to a more mild level of abuse.”

The study – published online in the journal JAMA Psychiatry in March and in print in May – analyzed data from more than 54,000 women who were participants in the Nurses’ Health Study II and reported that they had a child with autism spectrum disorder. They later received a questionnaire about childhood abuse.

“We looked at the mother’s exposure to abuse in childhood, both physical/emotional abuse, which is a combined measure, as well as sexual abuse and we looked at how the rates of having a child with autism differed by groups of women according to their child abuse status,” says Roberts. It is the first study that explores the relationship between a mother’s exposure to child abuse and the risk of autism in her children. While the study shows this association, the cause still remains unclear.

The study also looked at nine pregnancy-related risk factors in relation to abuse – such as gestational diabetes, preeclampsia, and smoking, finding “that women who experienced abuse were at higher risk of pretty much all of them,” says Roberts. “I think that’s a very important finding because it does suggest that abuse may well affect the health of the next generation – at minimum through these pregnancy-related risk factors,” she says.

Those risk factors accounted for only seven percent of the increased likelihood of having a child with autism among women who were abused, according to the release.

Alycia Halladay, Ph.D., senior director of environmental and clinical services for Autism Speaks, says there are two important messages from this study from the organization’s perspective.

“Number one, this should in no way be another study that in any way directs blame for childhood autism on anything that happened to the mother or what the mother did,” she says. “I know some women have really taken offense at  this article and said that this is just another way for women to take the blame or mothers to take the blame….The other thing that is important is that we are starting to understand how events in life prior to conception affect longer term outcomes in children.”

When it comes to longer-term outcomes, Roberts says psychologists can play an important role in reducing risk factors for future generations.

“[Psychologists] should be confident that their work is very important,” she says. “I think what our study shows is that the effects of abuse can cross generations and at least part of that is because of the effects on the women’s behavior and if psychologists are treating women or men who have experienced abuse, they are likely to reduce the probability that these people will engage in these harmful behaviors.”