Secular trends in birth weight, BMI, and diabetes in the offspring of diabetic mothers

OBJECTIVE - The offspring of mothers who had diabetes during pregnancy experience increased risk later of diabetes and obesity later. We hypothesized that, in light of the historical improvements in the management of diabetes during pregnancy, these late consequences of the early environment might be diminishing with time. RESEARCH DESIGN AND METHODS - Birth weight and information on BMI and glucose tolerance have been collected as part of the epidemiological survey of the Gila River Indian Community in Arizona. We examined birth weight, BMI, and diabetes in offspring of mothers with type 2 diabetes during pregnancy born in four 10-year time intervals since 1955 compared with offspring whose mothers either had not developed diabetes or were prediabetic (i.e., developed diabetes after the index pregnancy). RESULTS - Offspring of diabetic mothers (ODM) were heavier at birth, had a higher BMI at all ages throughout childhood, and had an increased incidence rate of diabetes in childhood and early adulthood (7- to 20-fold, offspring of nondiabetic mothers [ONDM]; 3- to 5-fold, offspring of prediabetic mothers [OPDM]). Relative differences in birth weight and BMI between ODM and ONDM were greatest for those born before 1965. In those born after 1965, despite secular trends to higher BMI and diabetes incidence in the ONDM, differences in BMI and birth weight of ODM versus ONDM and OPDM appeared to have been maintained. CONCLUSIONS - With the possible exception of individuals born before 1965, the increased risk of diabetes and obesity experienced by ODM does not seem to be diminishing with time.