Presence of GAD Antibodies During Gestational Diabetes Mellitus Predicts Type 1 Diabetes

OBJECTIVE - we sought to study the frequency of P-cell-specific autoantibody markers in women with gestational diabetes mellitus (GDM) and to follow these women to estimate the risk of later development of type I diabetes. RESEARCH DESIGN AND METHODS - Of 385 pregnant women with GDM during 1995-2005 in the district of Lund, 24 (6%) women were found positive for at least one of the following: islet cell antibody (ICA), GAD antibody (GADA), or tyrosine phosphatase antibody(IA-2A). The women were followed and autoantibodies reanalyzed. Those who had not developed diabetes did an oral glucose tolerance test. The frequencies of known risk factors; for GD were compared in women with GDM with and without pancreatic autoantibodies. RESULTS - Among the autoantibody-positive women, 50% had developed type I diabetes compared with none among the GDM control subjects (P = 0. 00 1), 2 1 % had impaired fasting glucose or impaired glucose tolerance compared with 12.5% among control subjects (P = 0.3), and none had developed type 2 diabetes compared with 12.5% among control subjects (P 0.1). CONCLUSIONS - Autoantibody screening in pregnant women with GDM and follow-up after delivery should be considered for early recognition of type I diabetes.