Autoimmune thyroid disease and insulin-dependent diabetes mellitus during pregnancy and post partum.

The aim of this study was to assess thyroid dysfunction and autoimmunity in pregnant insulin-dependent diabetes mellitus (IDDM) women during pregnancy and early post partum. Fifteen pregnant IDDM women and 77 healthy pregnant women were studied. Free T4, TSH, TPO-Ab and Tg-Ab were assayed during the first and third trimester of pregnancy and 3 months post partum. In IDDM women FT4 levels significantly decreased (p < 0.05) during third trimester and 3 months post partum and also TPO-Ab during third trimester (p < .01). 26% of IDDM and 4% of the controls presented post partum thyroid dysfunction. We recommend that prepregnant IDDM be screened for TPO-Ab. Those with a positive result would be followed with serial monitoring of free T4 and TSH levels during each trimester as well as during the post partum period.