Thyroid autoimmunity in pregnant women at risk for GDM

Presence of antithyroid autoantibodies (ThyAb) during pregnancy is strictly related to the risk of developing post partum thyroiditis (PPT) and this risk is increased in IDDM pregnant women. Gestational diabetes mellitus (GDM) is defined as carbohydrate intolerance of variable severity that begins, or is first diagnosed, during pregnancy. GDM is considered a risk factor for both type 1 and type 2 diabetes and various non-organ specific autoantibodies have been found to be associated with GDM, although there is little information on the association of GDM with thyroid autoimmunity. In this study oral glucose tolerance and prevalence of ThyAb were evaluated in a group of 41 pregnant women at increased risk of developing GDM and in a healthy control group. Our results showed that 22% of GDM risk group had impaired glucose gestational tolerance (IGGT) or GDM at the time of oral glucose tolerance test (OGTT). Moreover, ThyAb prevalence found in the women at increased risk of GDM (14.6%) was similar to that observed in healthy pregnant controls (12.5%). Nevertheless ThyAb frequency was higher in those GDM risk women with family history of diabetes (30.7%).