Programming for childhood obesity by pregnancy glycemia among Mexican-American women without diabetes or gestational diabetes

The prevalence of obesity is high among children of Mexican origin in the United States. Intra-uterine exposure to maternal diabetes is associated with childhood obesity, but the effects of lower levels of hyperglycemia are unknown. Multiple linear regression models were used to estimate the association between pregnancy glucose values, assessed 1-hour after a 50-g oral glucose tolerance test, and offspring BMI z-score at 2, 3.5, 5 and 7 years of age among 266 Mexican-American women without diabetes or gestational diabetes who participated in the CHAMACOS longitudinal cohort. Linear mixed effects models estimated the association between glucose value and BMI z-score trajectory from 2 to 7 years of age. Covariates included pre-pregnancy obesity, soda consumption, gestational weight gain, smoking, poverty, infant birth weight and gestational age at birth. Effect modification by pre-pregnancy obesity, gestational weight gain and infant birth weight was explored. Each mmol/L increase in pregnancy glucose value corresponded to a 0.12 unit (SD 0.045) increase in offspring BMI z-score at 7 years of age (p< 0.01). In non-obese women, increasing glucose values were significantly associated with an increased mean BMI z-score across the age range (β= 0.11, SD 0.04, p= 0.02); in obese women, there was a non-significant increase in BMI z-score velocity with increasing glucose (β = 0.035, SD 0.019; p= 0.07). These results suggest that levels of pregnancy hyperglycemia below those diagnostic of disease may be associated with subsequent childhood obesity. Thus, efforts to mitigate childhood obesity may potentially begin in utero.