Maternal prepregnancy body mass index and psychomotor development in children

Background. In a prospective study, the association between maternal nutritional status and psychomotor development of low-income African-American children was evaluated. We hypothesized that low maternal body mass index (BMI) would predict worse neurodevelopmental status in children, while higher maternal BMIs would be associated with better neurodevelopmental outcomes. Methods. Psychomotor tests for general intelligence and motor skills were given to 355 children at a mean age of 5.3 years. Maternal nutritional status was assessed by prepregnancy body mass index (BMI) and weight gain during pregnancy. Results. Fifty-four percent of the women in this study were overweight or obese. The means of the general IQ, nonverbal and verbal ability, and Gross Motor Scales of the children were 82.1+/-12.6, 87.4+/-15.7, 80.1+/-10.8 and 332.3+/-13.2, respectively. Seventeen percent of the children had general IQ scores of less than 70. To our surprise, in multiple regression analyses, adjusting for other covariates, maternal prepregnancy BMI was a significant negative predictor of IQ (beta=-0.25, P=0.001) and nonverbal ability (beta=-0.29, P=0.02). The IQ and nonverbal scores of children of women who were obese before pregnancy were approximately 5 units lower than for children whose mothers had a normal prepregnancy BMI. The other significant predictors of IQ and nonverbal scores of the children were childcare status (beta=3.5, P=0.04 and beta=0.26, P<0.0001, respectively) and the mother's receptive language scores (beta=5.2, P=0.01 and beta=0.25, P<0.0001, respectively). Conclusion. This study of low-income African-American children indicates that obese women are at risk of having children with diminished intellectual ability, but not motor skills.