Prevalence of postpartum thyroiditis in women with gestational diabetes mellitus in Ardabil: North West of Iran

Abstract

INTRODUCTIONGestational diabetes is the most common metabolic disorder during pregnancy that can cause serious complications for both mother and fetus.1 Therefore, identifying risk factors for gestational diabetes is of high importance, because by knowing these factors screening programs can be conducted for susceptible women. Additionally, maternal and fetal complications can be prevented by early diagnosis and proper control of blood glucose levels.2 Although, impaired glucose tolerance disappears after delivery in these patients; more than 70% of the patients are diagnosed with type 2 diabetes after 10 years.3,4 Postpartum thyroiditis is a destructive thyroiditis that can be induced one year after pregnancy via autoimmune mechanisms. Postpartum thyroiditis can also occur after spontaneous or induced abortion.5 This complication can occur in one the following three forms: transient hyperthyroidism, transient hypothyroidism, or hyperthyroidism followed by hypothyroidism, and then return to the normal state.The global incidence rate of postpartum thyroiditis varies from 1% to 17%. [6][7][8] The higher values (up to 25%) have been reported for women with type 1 diabetes, values higher than this (42%) have been observed in women with a previous history of postpartum thyroiditis, and the values ranging from 40 to 60% have been recorded for women with normal thyroid function during pregnancy but positive antiTPO.6,7 Most women within one year after delivery return to euthyroid state, however, some remain hypothyroid forever. 9-10Manifestation of ABSTRACT Background: Gestational diabetes is the most common metabolic disorder during pregnancy and postpartum thyroiditis is a destructive thyroiditis that can cause serious complications for the mother and her child. The purpose of this study was to determine the prevalence of postpartum thyroiditis in women with gestational diabetes. Methods: In this cross-sectional study, 86 cases satisfy inclusion criteria and gestational diabetes mellitus (GDM) and were evaluated for postpartum thyroiditis with thyroid stimulating hormone (TSH), T4, anti-TPO, T3RU tests. The groups with and without thyroiditis were compared and data was analyzed by statistical methods. Results: There were 17 patients (19.8%) with postpartum thyroiditis, of whom 4 patients (23.5%) had hyperthyroidism, 9 patients (52.9%) were in the age group of 21 to 30 years, and 9 patients (52.9%) had a family history of diabetes. Five patients (29.4%) with high anti-TPO level (P=0.022) and mean TSH and anti-TPO respectively, 2.8 (4.8) and 17.2 (35.9). Conclusions: The results showed that higher level of anti TPO titer and family history of diabetes can be associated with a higher rate of postpartum thyroiditis, so it is recommended that postpartum thyroiditis to be examined in women with gestational diabetes who have these mentioned items.