Obesity in pregnant women may cause IQ lag in boys

Obesity during pregnancy seems to be a common phenomenon, but it can affect the development of the child. Researchers in nutrition and environmental health from the University of Texas and Columbia University (USA) have discovered a link between a mother’s obesity during pregnancy and the development of her child.

The researchers found motor impairment in preschoolers, associated with lower middle childhood IQ in boys whose mothers were severely overweight during pregnancy. According to the research team, the differences are comparable to early childhood lead exposure. The results of their work were published on December 20 in the journal BMC Pediatrics.

During the study, the researchers observed 368 mothers and their children, all of similar economic status and living in similar neighborhoods, during their pregnancies and when the children were 3 and 7 years old.

Five IQ points less for boys

The researchers measured children’s motor skills at age 3 and found that maternal obesity during pregnancy was strongly associated with poorer motor performance in boys. New tests were repeated at age 7, and the results indicate that boys whose mothers were overweight or obese during pregnancy scored 5 or more points lower on comprehensive IQ tests, compared to boys whose mothers were of normal weight.

“Strikingly, even using different age-appropriate developmental assessments, we found these associations in infancy and middle childhood, meaning these effects persist over time,” Widen said. , assistant professor of nutritional sciences at the University of Texas. These results are not meant to shame or scare anyone. We are only beginning to understand some of these interactions between the weight of mothers and the health of their babies.”

Researchers still don’t know why obesity during pregnancy would affect a child’s future health. One of the explanations could be the fact that dietary and behavioral differences may be determining factors, or that the development of the fetus may be affected by certain mechanisms specific to overweight people.

Previous research has established links between a mother’s diet and cognitive development. Therefore, the researchers considered several factors in their analysis, including the mother’s ethnicity, marital status, education level and IQ, as well as whether the children were born prematurely or they have been exposed to environmental irritants such as air pollution.

A nurturing home environment can reduce the negative effects of obesity

During their research, the team also examined and took into account the environment in which the child lived, examining in particular how the parents interacted with their offspring, and whether the child received books and toys.

They found that a nurturing home environment could mitigate the negative effects of obesity. “The effect on IQ was weaker in a nurturing home environment, but it was still there,” says Elizabeth Widen. The child’s IQ can have long-term consequences. It can, according to the researchers, predict educational level, socio-economic status and professional success later in life. According to the study results, the effects can potentially last into adulthood.

In a 2018 study, mothers exposed to lead “provided” a lower performance IQ in boys, but not in girls. These results should be put into perspective with a 2019 study which suggests that boys whose mothers had received fluoride during their pregnancy obtained lower results on an assessment of their IQ.

The research team advises obese or overweight pregnant women to follow a balanced diet rich in fruits and vegetables, take a prenatal vitamin, stay active and ensure they consume enough fatty acids, such as those present in fish oil.

Giving children a nurturing home environment is extremely important, as is seeing a doctor regularly, including during pregnancy, to discuss weight gain. “Work with your doctor and discuss what is appropriate for your situation,” Elizabeth Widen concludes.