Maternal BMI Before Pregnancy, Maternal Weight Gain During Pregnancy, and Risk of Persistent Positivity for Multiple Diabetes-Associated Autoantibodies in Children With the High-Risk HLA Genotype The MIDIA study
Abstract
To assess whether maternal BMI before pregnancy and weight gain during pregnancy predicted the risk of islet autoimmunity in genetically susceptible children. Of 46,939 newborns screened for the high-risk HLA genotype DR4-DQ8/DR3-DQ2, 1,003 were positive and 885 were followed with serial blood samples tested for autoantibodies to insulin, GAD, and insulinoma-associated protein 2 (IA2).
The end point was defined as repeated positivity for two or three autoantibodies or the onset of type I diabetes (islet autoimmunity). Thirty-six children developed islet autoimmunity, of whom 10 developed type I diabetes.
Both maternal BMI >= 30 kg/m(2) before pregnancy and maternal weight gain >= 15 kg predicted the increased risk of islet autoimmunity (hazard ratio [HR] 2.5, P = 0.023, and HR 2.5, P = 0.015, respectively), independent of maternal diabetes. Maternal weight may predict risk of islet autoimmunity in offspring with a high genetic susceptibility to type 1 diabetes.