Excess Weight Among Pregnant Women May Interfere With Child's Developing Brain

Researchers at NYU Grossman School of Medicine revealed, after an investigation linked to high body mass index (BMI), that obesity in expectant mothers may hinder the development of the babies' brains.

According to the study, a high BMI can affect two brain areas, the prefrontal cortex, and anterior insula, regions that play a key role in decision-making and behavior. These disruptions have been previously linked to attention-deficit/hyperactivity disorder (ADHD), autism, and overeating.

During the research, the investigators examined 197 groups of metabolically active nerve cells in the fetal brain. The NYU Grossman School of Medicine informed that with the help of millions of computations, the study authors "divided the groups into 16 meaningful subgroups based on over 19,000 possible connections between the groups of neurons." After completing this process they found only two areas of the brain where their connections to each other were statistically strongly linked to the mother's BMI.

"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," says Moriah Thomason, Ph.D., the Barakett Associate Professor in the Department of Child and Adolescent Psychiatry at NYU Langone Health. Thomason, who is also an associate professor in the Department of Population Health at NYU Langone, added that it is more important than ever to understand how the condition may impact early brain development.

Previous studies only revealed that obesity had a cognitive function impact after birth, however, this new investigation is believed to be the first to measure changes in fetal brain activity in the womb, and as early as six months into pregnancy.

According to Thomason, this approach eliminates the idea that breastfeeding and other environmental factors occurring after birth are the only causes that can affect brain development.

The NYU Grossman School of Medicine informed that the research team recruited 109 women with BMIs ranging from 25 to 47. (According to the National Institutes of Health, women are considered "overweight" if they have a BMI of 25 or higher and are "obese" if their BMI is 30 and higher.) The women were all between six and nine months pregnant.

To measure fetal brain activity the research team used MRI imaging. Here they were able to map patterns of communication between large numbers of brain cells clustered together in different regions of the brain, to later compare it and identify differences in how groups of neurons communicate with each other based on BMI.

The investigators caution that their study was not designed to draw a direct line between the differences they found and the ultimate cognitive or behavioral problems in children. The study only looked at fetal brain activity. But, Thomason says, they now plan to follow the participants' children over time to determine whether the brain activity changes lead to ADHD, behavioral issues, and other health risks.

In addition to Thomason, other NYU researchers involved in the study included Carly Lenniger, BS. Megan Norr, BA, of the University of California Berkeley, served as the study lead author. Additional research support was provided by Jasmine Hect, BS, of Wayne State University in Detroit, Michigan, and Martijn van den Heuvel of VU University Medical Center in Amsterdam, the Netherlands.