In the latest study on autism, published in the journal JAMA Pediatrics, researchers have found that moms who induce or speed up labor are slightly more likely to have children with the brain disorder—13 percent more likely, to be exact. But before you go blaming the labor drugs, read on.
According to Simon Gregory, lead author of the study at the Duke Institute of Molecular Physiology, the common thread between labor induction and autism may have more to do with the fact that baby is arriving late in the first place.
"Infants destined to develop autism are less likely to send out the correct biochemical signals for normal progression of labor," says Tara Wenger, a pediatric genetics fellow at the Children's Hospital of Philadelphia who spoke with NPR about the study. That means that babies with the developmental disorder could simply not be indicating when it's time for them to make their exit from the womb, hence the need for induction at all.
For their research, scientists studied the cases of 625,042 North Carolina babies born over an eight-year period. They then compared the children's school records, which detailed whether or not they had autism.
Here's what they found: For kids born following an induced labor, their risk of autism was 13 percent higher than those who weren't. In cases where labor was sped up artificially, those kids had a 16 percent higher risk of autism. And in cases where both induction and augmentation were done together? That was linked to a significantly greater risk of autism—23 percent. A little more perspective on those numbers for you: Researchers estimate that 2 in every 1,000 autism cases could be totally eliminated if labor induction or augmentation were not used. Wow.
Of course, more research is needed to know more about the connection. After all, there are tons of other pregnancy complications and risk factors that boost the risk of developmental disorders—like if a baby is born early or underweight, if they're in distress during delivery, if they have older mothers or fathers or even if they're born within a year of their sibling.
Still, the study's findings are pretty significant.
Michael Rosanoff, the associate director of Autism Speaks, spoke about the study to TIME and said: “I think we’re at a point in autism research where we are really looking to uncover any possible risk factor. What this tells us is that the period around pregnancy is a very important stage in the development of a child. It seems to be a critical period for exposure to potential risk factors that might increase risk for autism. We are seeing that again in this study. It’s not a huge risk, but the fact that so many women may be exposed to this risk factor is what’s important and what warrants additional research into the actual mechanisms behind this association.”