Objective: Obesity is prevalent among women of reproductive age, and developmental disabilities in children continue to increase. We examined associations between mother's prepregnancy body mass index (BMI) and physical and developmental disabilities, and objective measures of reading and math skills and fine and gross motor function in children.
Methods: We used the Early Childhood Longitudinal Study-Birth Cohort (ECLS-B; n=5200), a cohort of children born in 2001 and followed until kindergarten. Children were classified according to maternal prepregnancy BMI (in kg per m(2)): underweight (BMI <18.5), normal weight (BMI 18.5-24.9), overweight (BMI 25.0-29.9), obese class I (BMI 30.0-34.9) and obese class II/III (BMI ≥ 35.0). Parent reports of doctor-diagnosed disabilities were collected up to kindergarten and classified as learning and behavioral or physical. Children's reading and math and fine and gross motor function were assessed at kindergarten according to standardized tests. Linear and modified logistic regression models were adjusted for maternal sociodemographic variables, family enrichment variables, and children's sex, age and year of kindergarten entry. Additional adjustment for current child BMI was performed in separate models. All data are weighted to be nationally representative of the children born in 2001.
Results: Compared with children of normal-weight mothers, children born to obese class II/III mothers had an increased risk of learning or behavioral (risk ratio 1.67; 95% confidence interval 1.27, 2.21)), but not physical disabilities (risk ratio 0.57; 95% confidence interval 0.27, 1.22). Gross (P<0.001), but not fine (P=0.06) motor function was significantly associated with maternal BMI, but gross motor function was attenuated after adjustment for current child BMI (P=0.05). Children's reading scores (P=0.01) but not math scores (P=0.11) were significantly associated with maternal BMI.
Conclusions: In this nationally representative US cohort, children born to severely obese mothers had an increased risk for diagnosed learning and behavioral but not physical disabilities by kindergarten.