Associations of maternal glycemia and prepregnancy BMI with early childhood growth: a prospective cohort study

The prevalence of maternal and child overweight/obesity and gestational hyperglycemia has increased greatly in China in recent years. However, studies examining the relationship between maternal hyperglycemia, maternal prepregnancy body mass index (ppBMI), and offspring obesity in China are limited. Here, we conducted a prospective study of 6684 mother-child pairs in Wuhan, China in 2012-2015. Maternal glucose concentrations were measured at approximately 24-28 weeks of gestation; children's weight and length were measured at birth and at 6, 12, and 24 months of age; and BMI-for-age Z-scores (BMIZ) were calculated for different time points. We found that maternal fasting plasma glucose (FPG) concentrations were positively associated with offspring ponderal index and the risk of macrosomia at birth, but not with BMIZ or the risk of overweight/obesity at 6, 12, and 24 months of age. By contrast, maternal ppBMI was positively associated with both an increased risk of macrosomia at birth and overweight/obesity at 6, 12, and 24 months of age. Here, we observed an interaction effect of the association of FPG and ppBMI on offspring macrosomia and a mediating effect of gestational diabetes mellitus on the pathway between ppBMI and macrosomia. Our findings suggest that maternal ppBMI is a more pronounced predictor than gestational FPG concentrations in both the relation to BMIZ and the risk of overweight/obesity in early childhood.