Abstract

OBJECTIVE--- To determine how the range of measured maternal glycemia in pregnancy relates to risk of obesity in childhood.

RESEARCH DESIGN AND METHODS--- Universal GDM screening (50g glucose-challenge test [GCT]) was performed in 2 regions (Northwest/Hawaii) of a large diverse HMO during 1995-2000, and GDM diagnosed/treated using a 3-hr 100g oral glucose tolerance test (OGTT) and National Diabetes Data Group (NDDG) criteria. Measured weight in offspring (n=9,439) was ascertained 5-7 years later to calculate gender-specific weight-for-age percentiles using USA norms (1963-1994 standard), then classified by maternal positive (+) GCT (1hr>=7.8mmol/l) and OGTT results ([1 or >=2 of the 4 timepoints abnormal; fasting, 1-hr, 2-hr, 3-hr] by Carpenter & Coustan (CC) and NDDG criteria).

RESULTS--- There was a positive trend for increasing childhood obesity at age 5-7 years (p<0.0001; 85%ile & 95%ile) across the range of increasing maternal glucose screen values, which remained after adjustment for potential confounders including maternal weight gain, maternal age, parity, ethnicity, and birthweight. The risk of childhood obesity in offspring of mothers with GDM by NDDG criteria (treated) was attenuated compared to the groups with lesser degrees of hyperglycemia (untreated). The relationships were similar among Caucasians and non-Caucasians. Stratification by birthweight also revealed these effects in children of normal birthweight (<=4000g).

CONCLUSIONS--- Our results in a multi-ethnic US population suggest that increasing hyperglycemia in pregnancy is associated with an increased risk of childhood obesity. More research is needed to determine if treatment of GDM may be a modifiable risk factor for childhood obesity.