The Relationship between Gestational Diabetes and Thyroid Hormone Levels among Pregnant Women in Zabol in 2021

Gestational diabetes is a degree of glucose intolerance that is first diagnosed or developed during pregnancy due to the inability of the pancreas to secrete more insulin to respond to increased insulin resistance or decreased insulin sensitivity. Many studies have shown that gestational diabetes mellitus (GDM) and thyroid dysfunction can have a variety of adverse effects on the outcomes of pregnancy and offspring. In the present study, the relationship between gestational diabetes and thyroid hormone levels was investigated in pregnant women in Zabol.

In this case-control study, 252 pregnant women (87 with and 165 without GDM) were randomly admitted during 2020. The serum levels of FBS, free thyroxine (FT4), and thyroid-stimulating hormone (TSH) were compared between the two groups. Data were analyzed using SPSS statistical software (version 22).

The mean TSH levels in the case and control groups were 2.75 ± 1.56 and 1.78 ± 1.07 μIU/mL, respectively, which was significantly higher in the case group (P < 0.00). Mean FT4 levels were 1.5 ± 0.61 and 1.4 ± 0.68 ng/ in case and control groups, respectively which were not statistically different in both groups (P = 0.25). Among patients with GDM, 16 (12.48%) had subclinical hypothyroidism and 6 (7.69%) had clinical hypothyroidism, while among non-GDM patients, 7 (4.24%) had subclinical hypothyroidism and 4 (2.42%) had clinical hypothyroidism.

These findings indicate a significant association between hypothyroidism and gestational diabetes. Therefore, accurate measurement and evaluation of thyroid hormones during pregnancy, especially in diabetic mothers, is recommended for better management and its prognosis.