Endocrine Abstracts

Introduction: Iodine may aggravate maternal autoimmune thyroid diseases during and after pregnancy, but selenium could defend against it’s harmful effect. Objective: to study the course and complications of Hashimoto’s thyroiditis in pregnant and lactating women receiving iodine and selenium therapy. Material and method. Serum TSH, free-T4 and anti-thyroid peroxidase-antibody were measured in 30 women with chronic autoimmune thyroiditis in every gestational trimester, on the 6th-7th postpartum week and at 6–9 months after delivery. They received 100 mcg/day selenium and 100–200 μg/day iodine ±L-thyroxine during the studied period. The results were compared to those of 30 women without chronic autoimmune thyroiditis, receiving 100–200 μg/day iodine ± L-thyroxine during pregnancy and lactation.

Results: In the thyroiditis group nine women were known with thyroid disease before pregnancy, and hypothyroidism developed in other 20 cases during pregnancy (27 hypothyroidism and two isolated hypothyroxinaemia). Thyroid function has not normalized yet in any of these cases. One imminent abortion and one imminent preterm delivery were noticed. In the postpartum period two cases of postpartum thyrotoxicosis with autolimited course and two cases of severe hypothyroidism developed. In women without chronic autoimmune thyroiditis no gestational or postpartum complications, no postpartum thyrotoxicosis appeared. In the second group nine cases of isolated hypothyroxinaemia were recorded, their proportion being mildly higher, at the limit of significance compared to the thyroiditis group (P=0.04). Conclusions. Hypothyroidism developed frequently among pregnant women with Hashimoto’s thyroiditis receiving iodine with selenium, but gestational and postpartum complications were not observed significantly more frequently in these women compared to those without chronic autoimmune thyroiditis.