Ultrasonographic characteristics and follow-up in post-partum thyroiditis.

Post-partum thyroiditis (PPT) is an autoimmune disorder of the thyroid gland, which occurs in the first year after parturition. This study was designed to evaluate sonographic characteristics in a group of PPT patients in Tehran. The study group consisted of 119 PPT patients and 97 normal post-partum women as the control group. Physical examination of thyroid and ultrasonography were carried out monthly in PPT patients until remission for up to 12 months post-partum and 65 patients were followed-up until the end of the study. Visible goiter was detected in 21.8% of patients and 6.7% of the control group (p < 0.001). Hypoechogenecity in thyroid sonography was present in 98.5% of patients and 7% of the control group (p < 0.001). Initially mean thyroid volume in PPT patients was found to be 77% more than that of the control group. After remission, mean thyroid volume decreased by 25% in PPT patients. At 12 months after delivery, only 6 patients had abnormal thyroid function tests, while 4 patients with TSH > 10 mU/I still showed hypoechogenicity in thyroid sonography. In conclusion, sonography may be recommended as an adjuvant to laboratory tests in evaluation of PPT patients.