This article is more than 5 years old. Information may no longer be current.

Maternal obesity linked to lower IQ, cognitive function in children

Mothers who are obese or overweight before pregnancy and who give birth at 28 weeks or less, are at an increased risk for having children that perform poorly in cognitive functions and score low on intelligence tests, according to findings recently published in The Journal of Pediatrics.

“Although the long-term neurodevelopmental and cognitive outcomes of children born preterm generally are well-described, less is known about antecedents and modifiers of this association,” Elizabeth T. Jensen, MPH, PhD, of the department of epidemiology and prevention at Wake Forest University Public Health Sciences, and colleagues wrote. “We are not aware of any study that assessed the relationship between the mother’s adiposity and her child’s neurocognitive function at age 10 years.”

More than one in three women of childbearing age in the United States is considered obese, according to the researchers.

Jensen and colleagues studied 535 children who had been previously enrolled in the Extremely Low Gestational Age Newborns cohort study. Their mothers had provided prepregnancy weight information right after delivery. The children took neurocognitive evaluations at 10 years of age.

Researchers found that children of mothers whose prepregnancy BMI was less than 18.5 were at increased odds of low scores on the Wechsler Individual Achievement Test-III Spelling assessment.

Conversely, children born to mothers with a preconception BMI between 25 and 30 had a greater likelihood of a low score on the Differential Ability Scales-II Working Memory, the Developmental Neuropsychological Assessment-II Inhibition Naming, and the Wechsler Individual Achievement Test-III Spelling exams.

Also, children whose mothers prepregnancy BMI was 30 or greater were at increased odds for low scores on the Differential Ability Scales-II Verbal IQ, Nonverbal IQ, and Working Memory, the Oral and Written Language Scales Oral Expression, the Developmental Neuropsychological Assessment-II Inhibition Naming and Visuomotor Precision, and all four Wechsler Individual Achievement Test-III assessments.

Jensen and colleagues further noted that after adjustment for potential confounders such as the offspring’s sex, maternal educational level and ethnicity, and if the mother met the requirements for government-provided insurance, children of mothers whose preconception BMI was 30 or greater were more likely to have low scores on the Differential Ability Scales-II Verbal IQ, the Developmental Neuropsychological Assessment-II Inhibition Naming and Visuomotor Precision assessments, and only the Spelling component of the Wechsler Individual Achievement Test-III.

“Although the findings do not establish causality, they do suggest that behavioral interventions to reduce prepregnancy weight among women might mitigate some of these impairments in their children born preterm,” Jensen said in a press release.

Researchers also noted that their findings mirror shorter-term studies of children born at term. – by Janel Miller

Disclosure: The researchers report no relevant financial disclosures.