Résumé
The relationship between maternal obesity and childhood cognitive development remains unclear. Prior studies did not adjust for important confounders, and preterm infants are a developmentally distinct group that remains scarcely examined.
To determine whether maternal prepregnancy body mass index (BMI) is associated with offspring intelligence quotient (IQ) up to 5 years and whether this relationship varies with gestational age.
Data from two French birth cohorts, EDEN (all gestational ages) and EPIPAGE-2 (preterm children born between 24 and 34 weeks of gestation), were used for this study. Maternal prepregnancy weight and height were used to calculate prepregnancy BMI. The Wechsler Preschool and Primary Scale of Intelligence was used to assess child IQ around 5 years. Multivariable models were adjusted for confounders, including socioeconomic status and paternal BMI.
Analytical cohorts included 1100 children from EDEN and 2629 from EPIPAGE-2. Lower intellectual functioning (full-scale IQ < 85) was observed in 8.1% of children in EDEN and 19.6% in EPIPAGE-2. The prevalence of maternal obesity was 13.6% (EDEN) and 21.3% (EPIPAGE-2) among children with lower intellectual functioning compared to 8.9% (EDEN) and 12.9% (EPIPAGE-2) among children with normal intellectual functioning. Maternal prepregnancy obesity was associated with an approximately 3-point decrease in full-scale IQ scores in fully adjusted models (adjusted β -2.8, 95% confidence interval [CI] -5.6, -0.1 and -2.6, 95% CI -4.7, -0.6 in EDEN and EPIPAGE-2, respectively). In EDEN, maternal obesity was associated with lower scores in the verbal IQ domain. Among infants born preterm (EPIPAGE-2), maternal obesity was associated with lower scores in the processing, reasoning, and verbal IQ domains. Adjustment for paternal BMI did not change the magnitude of the relationship with maternal obesity.
High maternal prepregnancy BMI is associated with child cognitive development around 5 years of age.