The influence of selenium supplementation on postpartum thyroid status in pregnant women with thyroid peroxidase autoantibodies.

CONTEXT: Pregnant women who are positive for thyroid peroxidase antibodies [TPOAb(+)] are prone to develop postpartum thyroid dysfunction (PPTD) and permanent hypothyroidism. Selenium (Se) decreases thyroid inflammatory activity in patients with autoimmune thyroiditis.

OBJECTIVE

We examined whether Se supplementation, during and after pregnancy, influences the thyroidal autoimmune pattern and function.

DESIGN

This was a prospective, randomized, placebo-controlled study.

SETTING

The study was conducted in the Department of Obstetrics and Gynecology and Department of Endocrinology.

PATIENTS: A total of 2143 euthyroid pregnant women participated in the study; 7.9% were TPOAb(+).

INTERVENTIONS: During pregnancy and the postpartum period, 77 TPOAb(+) women received selenomethionine 200 microg/d (group S1), 74 TPOAb(+) women received placebo (group S0), and 81 TPOAb(-) age-matched women were the control group (group C).

MAIN OUTCOME MEASURES: We measured the prevalence of PPTD and hypothyroidism.

RESULTS

PPTD and permanent hypothyroidism were significantly lower in group S1 compared with S0 (28.6 vs. 48.6%, P<0.01; and 11.7 vs. 20.3%, P<0.01).

CONCLUSION

Se supplementation during pregnancy and in the postpartum period reduced thyroid inflammatory activity and the incidence of hypothyroidism.