Postpartum thyroid dysfunction in Bangkok: A geographical variation in the prevalence

Abstract

To determine the prevalence of thyroid dysfunction in Thai postpartum women, we evaluated thyroid function and thyroid autoantibodies in 812 consecutive unselected women at 1.5 months post partum. At 3.5 months post partum 570 women without previous thyroid abnormality returned for a second set of thyroid function test. The prevalence of thyroid dysfunction was 1.1%, which was less than that reported from other countries. Various types of postpartum thyroid dysfunction, namely, transient thyrotoxicosis followed by transient hypothyroidism, transient thyrotoxicosis or hypothyroidism occurring alone or permanent hypothyroidism were encountered. Eight out of 9 patients with thyroid dysfunction had thyroid autoantibodies. Fine needle aspiration biopsy of the thyroid was done in 4 patients and all showed lymphocytic thyroiditis. Even though Bangkok is an iodine surfeit area, iodine intake is relatively lower than in other areas where the prevalence of postpartum thyroid dysfunction is much higher. The discrepancy in geographic prevalence of postpartum thyroid dysfunction may result from the interaction of immunogenetic heterogeneity of different ethnic background, environmental iodine intake, and other unidentified environmental factors.

Prevalence and characteristics of postpartum thyroid dysfunction in Tehran

“…The rate of PPT in countries with iodine de®ciency has been reported to be low (6). It is conceivable that an increase in PPT, such as that reported for thyrotoxicosis, may have occurred in Tehranian women following consumption of iodized salt used to control iodine-de®ciency disorders.…”

CTLA-4 in autoimmune diseases – a general susceptibility gene to autoimmunity?

“…120 Significant differences in prevalence between ethnic groups have been reported. 121 Results from genetic studies of the HLA region in PPT have been conflicting. 122,123 As the CTLA4 polymorphisms associate with AITD, CTLA4 are considered a putative candidate gene in PPT.…”

Recurrent Postpartum Thyroiditis in a Patient With Chronic Autoimmune Thyroiditis: A Case Report

“…Most patients have normal thyroid function at one year [10], and all three episodes in the present case recovered within one year. Abortion is a common clinical problem, and several studies have revealed a strong correlation between presence of thyroid antibodies and spontaneous abortion [11][12][13]. Bagis et al [3] reported that 50% of thyroid autoantibody-positive women and 14.1% of thyroid autoantibody-negative patients had a history of spontaneous abortion.…”