Endocrine Abstracts

Background: Pregnancy alters the natural history of autoimmune thyroid disorders. The incidence rate of positive thyroid antibodies (T-abs +) in asymptomatic women during pregnancy has been reported to be between 6 and 19.6%.

Aim: To determine the prevalence of thyroid antibodies (T-abs) in Gestational Diabetes Mellitus (GDM).

Subjects & Method: In 408 women, at the time of diagnose of GDM, TSH, free thyroxine, free tri-iodothyronine and anti-thyroid antibodies (T-abs) (thyroperoxidase and thyroglobulin) were measured. In these women we evaluated: previous thyroid disease, maternal age, BMI, spontaneous abortion, first degree relatives with D.M., Sullivan and OGTT values, insulin needed for diabetes control, new-born weight, gestational age at the time of GD diagnose and at delivery, evaluation of glucose tolerance after delivery. Statistical analysis involved SPSS (Statistical Analysis for Social Sciences); P<0.05 was considered to indicate statistical significance.

Results: From the women (408) who were enrolled in the study 21(5.1%) had positive T-abs. Only 20 women had thyroid disease (2%), with no direct relation with the presence of T-abs. The presence of T-abs + had a positive correlation with type 1 DM abs (r=0.202, P<0.001). There was no correlation between T-abs + and TSH, free thyroxine and free tri-iodothyronine values, as well as with the other maternal and fetal variables.

Conclusion: The results revealed a prevalence of autoimmune thyroid disease of 5.1% in women with GDM, identical to normal pregnant women, thus this measurement should not be systematic in women with GDM during prenancy. However, in the sub-group of GDM with type 1 DM positive abs, the positive correlation founded, suggests a systematic screening for T-abs. These data reinforce the importance of screening of latent pluri glandular auto immune disorders during pregnancy in women prone for those.