Controlling for all other variables, the analysis showed that maternal prepregnancy obesity was negatively associated with math and reading test scores. Children of obese women scored, on average, three points lower on reading and two points lower on math than did children of healthy-weight women. The mean reading score among all the children was 106.1 points and the mean math score was 99.9.
Though the score differences seem small, Tanda noted that these effects of prepregnancy obesity were equivalent to a seven-year decrease in the mothers’ education and significantly lower family income, two other known risk factors that negatively affect childhood cognitive function.
Tanda said clinicians could use these findings to help encourage women patients of childbearing age to maintain a healthy weight, especially if they plan to get pregnant.
Prepregnancy Obesity Linked to Asthma in Teens
Children of women who are overweight or obese when they become pregnant may be more likely to have asthma by the time of adolescence, a new study shows.
Researchers in Britain, Finland, and Sweden say their study suggests that being overweight during pregnancy may interfere with normal fetal development, though it does not prove a cause-and-effect relationship.
The study found that asthma-like respiratory symptoms such as wheezing were up to 30% more likely when children were teenagers if mothers were overweight or obese during fetal development.
“This is a large population study, so at the individual level we can’t say that one person’s decision to change her weight will change her child’s outcome,” she said. “But these findings suggest that children born to women who are obese before pregnancy might need extra support.”
Added Salsberry, “It’s not only for their child’s sake. It’s also important for the health of the mother. But it is important to understand that maternal obesity during pregnancy could have implications for their children as well.”
Obesity is linked to chronic conditions such as high blood pressure, heart disease, diabetes, and stroke.
Women who are obese prior to pregnancy are at increased risk of developing gestational diabetes, pregnancy-related hypertension, preeclampsia, and labor complications; and their infants are at increased risk for neonatal death.
• More than one-third (36.3 percent) of Oregon births in 2004 were to women who were overweight or obese prior to pregnancy.
• Almost half (47.1 percent) of American Indian/Alaska Native women were overweight/obese prior to pregnancy. This percentage was significantly higher than that of white (36.0 percent) or Asian/Pacific Islander (20.1 percent) women.
• Asian/Pacific Islander women were significantly less likely than any other race/ethnic group to be overweight/obese before pregnancy (20.1 percent).
Without actual measures of women’s and fetuses’ insulin levels, inflammation and blood sugar readings, scientists can’t say for sure how prepregnancy obesity might affect the fetal brain. But previous studies have suggested that a mother’s impaired metabolic processes affect the fetal brain cell growth and formation of synapses.
The researchers also noted that obesity doesn’t automatically equate to unhealthy.
“There may be two obese moms that in fact have very different metabolic profiles. For the purposes of this study, her weight is a stand-in for biological data that we would like to have but don’t,” Salsberry said.
Socioeconomic data from the study supported previous findings that several post-birth conditions can have a positive association with higher children’s test scores. These include a stimulating home environment with plenty of books, a safe play environment and frequent family meals; higher family income; and higher maternal education levels and cognitive function. Girls and first-born children also performed better on the math and reading tests than did boys and younger siblings.
With all these data combined, Tanda said, the study also reveals how health disparities can have long-lasting effects.
“Young females who grow up poor, who have less access to healthy foods resulting in diets that are of poorer quality, are at higher risk of having children with disadvantages and repeating this cycle,” she said.
The researchers are continuing to examine additional influences on childhood cognition, including race, sex and age differences among mothers.
This study was supported by a grant from the Ruth L. Kirschstein National Research Service Award predoctoral fellowship sponsored by the National Institute of Nursing Research.
Additional co-authors included Patricia Reagan and Muriel Fang of Ohio State’s Department of Economics and the Center for Human Resource Research.