Maternal obesity during pregnancy linked to behavior problems in boys

The heavier the mothers are when entering pregnancy, the higher the risks that their sons will develop behavior problems, a new study finds. The same effect was not observed for girls, the scientists point out. 

With obesity on the rise, more and more women enter pregnancy while also battling with extra pounds. But this increase in the weight of the future mother can have side effects for the developing child, as scientists are probing to find the link between obesity and the rise in child neurodevelopmental problems.

A new study published in the American Journal of Preventive Medicine proves just that. Mother with heavier weight have increased chances of giving birth to boys that develop behavior problems by the time their 9 or 11. The study also found that boys whose mothers were underweight pre-pregnancy also showed higher risk for behavior problems. But the same effect has not been observed on boys, the scientists say.

“Past research looking at a variety of exposures during pregnancy (ranging from stress to chemicals) has shown that boys tend to be more vulnerable to these exposures in utero than girls,” explained investigator Juliana Deardorff, PhD, of the Community Health Sciences Division, School of Public Health, University of California, Berkeley. “Our study extends this work to maternal obesity. It is the first study to document gender differences, and one of a handful of studies to show that pre-pregnancy underweight, in addition to obesity, may be problematic. Future research should examine whether the gender differences reported here for ages 9-11 years persist into adolescence or shift as children get older.”

The scientists point out the necessity for women to enter pregnancy with a healthy weight.

“The study results suggest that early intervention with women to attain healthy weights before they become pregnant is critical to their health and the health of their future children,” said senior investigator Barbara Abrams, Dr. PH, of the Division of Epidemiology, School of Public Health, University of California, Berkeley.

The Centers for Disease Control and Prevention estimates that in America, 15 out of every 100 women of childbearing age are severely obese.

Obesity not only affects the new-born babies but also the mothers. Maternal overweight and obesity is the most common high-risk obstetric condition and is associated gestational diabetes mellitus, hypertensive disorders, and newborn macrosomia, among other perinatal complications.

And gaining too much weight during pregnancy can also be dangerous as a previous 2009 study pointed out that excessive gestational weight gain contributes to higher postpartum body weight; however, higher maternal body size before pregnancy and biologic factors are also important.