Mom's Weight & Kids' Test Scores

Obesity before pregnancy associated with lower test scores for children

(RxWiki News) Shedding pounds before getting pregnant can reduce a number of health risks - but it may also add a few points to your child's reading and math scores.

A recent study has found a link between a mother's weight before pregnancy and their children's cognitive skills: obese women's children score lower on math and reading tests when they were 5 to 7 years old.

"Get to a healthy weight before becoming pregnant."

Lead author Rika Tanda, a nursing doctoral candidate at Ohio State University, and colleagues wanted to investigate potential connections between a mother's pre-pregnancy obesity and a developing baby's brain.

Past research has found associations between pre-pregnancy obesity and problems with various organs in fetus, such as the heart, liver and pancreas.

Studies have also found that the brain development of a fetus may be linked to the home environment, family income and the mother's brain power and education level.

The researchers gathered information on 3,412 children born to participants of the National Longitudinal Survey of Youth 1979 Mother and Child Survey, whose nationally representative men and women were between 14 and 21 years old in December, 1978.

The women studied were classified as having a normal weight or being obese based on their body mass index, a ratio of their height and weight.

Over half the women were at a normal weight before becoming pregnant, and 9.6 percent were obese with a BMI of 30 or above.

Tanda and colleagues interviewed these women's children when the kids were between 5 and 7 years old. Children who were born early or late, or who had diagnosed physical or cognitive problems, were excluded from the study.

The children were given the math and reading sections of the Peabody Individual Achievement Test.

Those who mothers were obese scored three points lower on the reading assessment and two points lower on the math, even after researchers took into account the other factors that might influence the students' cognitive development.

The average score among all the kids who tested in was 106.1 for reading and 99.9 for math.

The score differences were similar to the effects seen on a child's score when the mother has seven years less of education or a significantly lower family income, both of which have been linked to a child's cognitive skills.

"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," Tanda said.

"But these findings suggest that children born to women who are obese before pregnancy might need extra support," she said.

To know more specifically about how being obese before a woman becomes pregnant might affect her baby's brain once she's pregnant, doctors would need to measure the woman and her baby's insulin levels, blood sugar and inflammation.

Pamela Salsberry, an Ohio State nursing professor who is a senior author on the paper, said using BMI is only a rough estimate of risks since they did not have more specific biological information on the women studied, and individual cases would vary.

The study also included background research on ways to increase the likelihood that a child will develop a stronger brain.

These include having lots of book in the house, a safe place for children to play, frequent family meals, a higher family income and a higher level of education and cognitive function in the child's mother.

The study appeared online in May in the Maternal and Child Health Journal. The research was funded by a grant from the Ruth L. Kirschstein National Research Service Aware predoctoral fellowship sponsored by the National Institute of Nursing Research.

Review Date: 
May 10, 2012