Obesity in pregnancy may hinder brain development

"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 E. Thomason. (Credit: Alice Fontana/Flickr)

Obesity in pregnant women may hinder the development of fetal brains as early as the second trimester, researchers report.

Their new study links high body mass index (BMI), an indicator of obesity, to changes in two brain areas, the prefrontal cortex and anterior insula. These regions play a key role in decision-making and behavior.

Previous studies have linked disruptions in these regions to attention deficit hyperactivity disorder (ADHD), autism, and overeating.

As reported in the Journal of Child Psychology and Psychiatry, the investigators examined 197 groups of metabolically active nerve cells in the fetal brain. Using millions of computations, the study authors divided the groups into 16 meaningful subgroups based on more than 19,000 possible connections between the groups of neurons. 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 E. Thomason, associate professor of child and adolescent psychiatry in the child and adolescent psychiatry department at New York University Langone Health.

As obesity rates continue to soar in the United States, it is more important than ever to understand how the condition may affect early brain development, says Thomason, who is also an associate professor in the population health department.

Previous studies showing an association between obesity and brain development had mostly looked at cognitive function in children after birth. The researchers believe the new investigation is the first to measure changes in fetal brain activity in the womb, and as early as six months into pregnancy.

Thomason says the researchers designed the approach to eliminate the potential influence of breast feeding and other environmental factors occurring after birth and to examine the earliest origins of negative effects of maternal BMI on the developing child’s brain.

For the investigation, the 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.

The team used MRI imaging to measure fetal brain activity and map patterns of communication between large numbers of brain cells clustered together in different regions of the brain. Then, they compared the study participants to identify differences in how groups of neurons communicate with each other based on BMI.

The investigators caution they did not design the study to draw a direct line between the differences they found and 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.

Additional coauthors are from the University of California, Berkeley; Wayne State University; and the VU University Medical Center in Amsterdam.

The National Institutes of Health funded the work.

Source: NYU