Follow up of patients with postpartum thyroiditis - A population-based study

In this survey we studied the prevalence of permanent hypothyroidism and prognostic factors for its occurrence 3-5 yr after postpartum thyroiditis (PPT); 54 of 120 women with PPT and 50 of 920 healthy women from among 1040 women followed 4-5 yr earlier for PPT were recalled. Demographic information, signs, and symptoms of thyroid disorders and results of physical exams were documented. Serum T-3, T-4, RT3U, TSH, and antithyroperoxidase (antiTPO ab) and antithyrogluboline (antiTg ab) antibodies were measured. Twenty-two percent of the cases and four percent of the control group had permanent hypothyroidism, p < 0.01. Based on the TSH level we divided the case group into two subgroups: PPT-Hypothyroidism (PPT-Hypo) and PPT-Eutyhroidism (PPT-EU); PPT-Hypo had greater titer of antiTPO ab than PPT-Eu (437 +/- 283 vs 126 +/- 221 IU/mL, p < 0.001). Comparison of mean peak serum TSH level and antiTPO A during the postpartum thyroiditis phase between PPT-Hypo and PPT-Eu in the case group was significant (56 +/- 24 vs 23 +/- 28 mU/L, p < 0.001, and 1960 +/- 1270 vs 640 +/- 959 IU/L, p < 0.001, respectively). Results of this survey show a high prevalence of permanent hypothyroidism following PPT in Tehran. High titers of antiTPOAb and TSH levels at postpartum period are prognostic factors for occurrence of permanent hypothyroidism.