Boys and Risk in Utero

Fetal ultrasound.

The delicate sex tends to be boys—at least in utero. Studies have found that boys appear to be more vulnerable in the womb. When mothers faced exposure to lead or even fluoride, researchers have detected an impact on IQ later in life for their boys, though not for their girls. The latest research from The University of Texas at Austin indicates another aspect of a pregnant mother’s experience may affect boys especially: their mother’s prepregnancy body weight.

Along with Columbia University researchers, the Texas team aimed to address the impact of obesity in pregnancy by studying 368 mothers and their children before children were born and again when they were 3 and 7 years of age. The research found that boys whose mothers had obesity while expecting them had impaired motor skills at age 3 and lower IQ at age 7. No such effect was found in girls. The differences are comparable to the impact of lead exposure in early childhood.

Elizabeth Widen, the UT Austin nutritional sciences assistant professor who led the study, noted that the research also found that a nurturing home environment helped to lessen the negative effects of obesity on children. She recommended women who are affected by obesity or being overweight discuss this with their doctors, and when they become pregnant, choose a well-balanced diet that is rich in fruits and vegetables, take a prenatal vitamin, stay active and get enough fatty acids.

“These findings aren’t meant to shame or scare anyone,” she said. “We are just beginning to understand some of these interactions between mothers’ weight and the health of their babies.”