Postpartum thyroid dysfunction in an Italian population residing in an area of mild iodine deficiency.

We have evaluated the occurrence of postpartum thyroid dysfunction (PPTD) in a group of 372 women residing in area of mild iodine deficiency. Thyroid function and autoimmune status were evaluated by means serum T4, T3, TSH measurement and detecting the presence of positive antithyroglobulin antibodies (AbTg), antimicrosomal antibodies (AbM) and thyroid-peroxidase antibodies (AbTPO) titers in women at parturition, at 1, 3, 6 and 12 months postpartum. New onset transient hypothyroidism occurred in 6.4% of women whereas transient thyrotoxicosis in only 1.8% of women. Transient hypothyroidism was not preceded by thyrotoxicosis as indicated by thyroid function tests and serum Tg concentrations. At parturition, the positivity of AbM and AbTPO titers and the presence of goiter appeared to be a risk factors for the development of PPTD.