According to a new study from Harvard School of Public Health (HSPH), women who experienced physical, emotional or sexual abuse as children are more likely to have an autistic child than women who were not abused.
The study, which was released online in March 2013, states that women who experienced the most serious abuse had the highest likelihood of having a child with autism – three-and-a-half times more than those who did not.
“Our study identifies a completely new risk factor for autism,” said lead author Andrea Roberts, research associate in the HSPH Department of Social and Behavioral Sciences.“Further research to understand how a woman’s experience of abuse is associated with autism in her children may help us better understand the causes of autism and identify possible risk factors,” she said.
According to Autism Speaks, the world’s leading autism science and advocacy organization, Autism Spectrum Disorder (ASD) and autism are brain development disorders characterized by varying degrees of difficulty in social interaction, verbal and non-verbal communication and repetitive behaviors. ASD can be linked to intellectual disability and difficulties in motor coordination. Autism seems to have its roots in very early brain development, but the most obvious symptoms materialize between two and three years of age.
In the United States, an estimated 1 in 54 boys and 1 in 252 girls are diagnosed with autism. ASD affects more than two million individuals in the U.S. and tens of millions worldwide.
Over the past five years, scientists have found that autism may be caused by a number of rare gene changes or mutations. However, most cases seem to be caused by environmental factors and autism risk genes which affect early brain development.
After examining data from more than 50,000 women enrolled in the Nurses’ Health Study II, the authors discovered that women who experienced the most abuse were 60 percent more likely to have a child with autism. Women exposed to moderate abuse had equal risk of having an autistic child as those exposed to serious abuse levels.
Additionally, researchers discovered that nine pregnancy related risk factors including gestational diabetes, preeclampsia and smoking were linked to increased risk of having a child with autism.
However, since these factors had little to do with the link between exposure to abuse and risk of autism, the authors assumed other factors may be responsible. They said one possibility is that long-lasting affects of abuse on the immune system and stress-response system increases their risk of having an autistic child.
Roberts recommended exercise and meditation for pregnant women to relieve stress. Professional counseling can also help women deal with past abuse. More research is needed to find out about the connection between childhood abuse and autism.
“Childhood abuse is associated with a wide array of health problems in the person who experiences it, including both mental health outcomes like depression and anxiety, and physical health outcomes like obesity and lung disease,” said senior author Marc Weisskopf, associate professor of environmental and occupational epidemiology at HSPH. “Our research suggests that the effects of childhood abuse may also reach across generations,” he said.
The authors suggested coming up with solutions to prevent childhood abuse based on the findings in this study and also suggested clinicians place more emphasis on limiting pregnancy-related autism risk factors, particularly among women who experienced abuse in childhood.