Gaining weight during pregnancy is natural and healthy — to a point. Excessive weight gain during pregnancy, however, is not healthy for women's hearts and can make a child more likely to become overweight. And now a study of prenatal brain development suggests that if a mother-to-be is obese, it can increase the likelihood of attention problems, autism and behavior issues.
The study took a close look at how a woman's body mass index (BMI), an indicator of obesity, affected two brain areas that play a key role in decision-making and behavior, investigating nearly 200 groups of metabolically active nerve cells in the fetal brain.
Based on over 19,000 possible connections among the groups of neurons, researchers from New York University's Grossman School of Medicine divided these groups into 16 meaningful subgroups and found two areas of the brain where their connections to each other were statistically strongly linked to the mother's BMI.
Disruptions in the prefrontal cortex and anterior insula have already been linked to attention-deficit/hyperactivity disorder (ADHD), autism, and overeating.
Of course, being overweight or obese isn't good for adult brains either.
“Our findings affirm that a mother's obesity may play a role in fetal brain development, which might explain some of the cognitive and metabolic health concerns seen in children born to mothers with higher BMI," Moriah Thomason, the Barakett Associate Professor in the Department of Child and Adolescent Psychiatry at NYU Langone Health, said in a statement.
Over 100 women with BMIs ranging from 25 to 47 took part in the study. According to the National Institutes of Health, a woman is overweight if she has a BMI of 25, and is considered obese if her body mass is 30 or higher. All the women in the study were between six and nine months' pregnant.
Obesity rates continue to soar in the United States, making it more important than ever to understand how the condition may impact early brain development, Thomason added.
The findings suggest that brain development is hindered in children of obese mothers even in the womb. The study only examined fetal brain activity, however. It was not designed to make a clear cause and effect connection between the differences noted and specific cognitive or behavioral problems in children in the future. The researchers do plan to follow the participants' children over time to determine whether the brain activity changes lead to ADHD, behavioral issues and other health risks.
The study is published in the Journal of Child Psychology and Psychiatry.