The relationship between thyroid dysfunction during pregnancy and gestational diabetes mellitus
Abstract
Introduction: Thyroid dysfunction and gestational diabetes (GDM) are the two most common endocrine disorders that can be observed during pregnancy. Thyroid function abnormalities can be associated with insulin resistance (IR) and changes in carbohydrate metabolism. In patients with type 1 diabetes, thyroid function is usually evaluated to rule out abnormalities within a second autoimmune disease. Patients with type 2 diabetes are tested for thyroid function in view of the associated weight gain, IR, and changes in metabolism. The question arises: Should we also look for thyroid dysfunction in patients with gestational diabetes? The aim of the study was to determine whether there are abnormalities in thyroid hormone levels in pregnant women with gestational diabetes.
Material and methods: A monocentric, retrospective study of the Dr Shterev Hospital electronic database was performed. We analysed the medical records of 662 pregnant women, divided in two groups — 412 with GDM and 250 with normal glucose tolerance, who gave birth in the period 2017–2019. Gestational diabetes mellitus in the study group was diagnosed with a 2-h, 75-g oral glucose tolerance test (OGTT) using the International Federation of Gynaecology and Obstetrics (FIGO) and American Diabetes Association (ADA) criteria. We analysed the mean serum concentrations of thyroid-stimulating hormone (TSH); free thyroxine (FT4), free triiodothyronine (FT3), FT3:FT4 ratio, fasting plasma glucose, age and body mass index in both groups. The groups were compared using the Mann-Whitney U-test.
Results: In patients who developed GDM, significantly higher concentrations of TSH (p < 0.0001) and FT3 (p < 0.0001), lower concentrations of FT4 (p < 0.0001), and higher FT3:FT4 ratios (p < 0.0001) were found.
Conclusion: The results of this pilot retrospective series reveal that high-normal to high concentration of TSH and low-normal to low concentration of FT4 as well as high FT3:Ft4 ratio could indicate increased risk of development of GDM.
Keywords: thyroid dysfunctionpregnancyinsulin resistancegestational diabetes mellitus
References
- Hage M, Zantout MS, Azar ST. Thyroid disorders and diabetes mellitus. J Thyroid Res. 2011; 2011: 439463.
- Stohl HE, Ouzounian J, Rick AM, et al. Thyroid disease and gestational diabetes mellitus (GDM): is there a connection? J Matern Fetal Neonatal Med. 2013; 26(11): 1139–1142.
- Perros P, McCrimmon RJ, Shaw G, et al. Frequency of thyroid dysfunction in diabetic patients: value of annual screening. Diabet Med. 1995; 12(7): 622–627.
- Gray RS, Borsey DQ, Seth J, et al. Prevalence of subclinical thyroid failure in insulin-dependent diabetes. J Clin Endocrinol Metab. 1980; 50(6): 1034–1037.
- Chubb SAP, Davis WA, Inman Z, et al. Prevalence and progression of subclinical hypothyroidism in women with type 2 diabetes: the Fremantle Diabetes Study. Clin Endocrinol (Oxf). 2005; 62(4): 480–486.
- International Diabetes Federation. IDF Diabetes Atlas. 9th ed. International Diabetes Federation, Brussels 2019.
- Bodmer-Roy S, Morin L, Cousineau J, et al. Pregnancy outcomes in women with and without gestational diabetes mellitus according to the International Association of the Diabetes and Pregnancy Study Groups criteria. Obstet Gynecol. 2012; 120(4): 746–752.
- Lee KW, Ching SM, Ramachandran V, et al. Prevalence and risk factors of gestational diabetes mellitus in Asia: a systematic review and meta-analysis. BMC Pregnancy Childbirth. 2018; 18(1): 494.
- Svare JA, Hansen BB, Mølsted-Pedersen L. Perinatal complications in women with gestational diabetes mellitus. Acta Obstet Gynecol Scand. 2001; 80(10): 899–904.
- Rosario PW, Carvalho M, Calsolari MR. TSH reference values in the first trimester of gestation and correlation between maternal TSH and obstetric and neonatal outcomes: a prospective Brazilian study. Arch Endocrinol Metab. 2016; 60(4): 314–318.
- American Diabetes Association. 2. Classification and Diagnosis of Diabetes: Standards of Medical Care in Diabetes—2020. Diab Care. 2019; 43(Suppl 1): S14–S31.
- Bulgarian Society of Endocrinology. Recommendations for good clinical practice for Diabetes Mellitus [In Bulgarian]. Bulgarian Society of Endocrinology, Sofia 2019.
- Hod M, Kapur A, Sacks D, et al. The International Federation of Gynecology and Obstetrics (FIGO) Initiative on gestational diabetes mellitus: A pragmatic guide for diagnosis, management, and care#. Int J Gynaecol Obstet. 2015; 131: S173–S211.
- Alexander EK, Pearce EN, Brent GA, et al. 2017 Guidelines of the American Thyroid Association for the Diagnosis and Management of Thyroid Disease During Pregnancy and the Postpartum. Thyroid. 2017; 27(3): 315–389.
- Bulgarian Society of Endocrinology. Recommendations for good clinical practice for thyroid disease [in Bulgarian]. Bulgarian Society of Endocrinology, Sofia 2019.
- De Groot L, Abalovich M, Alexander EK, et al. Management of thyroid dysfunction during pregnancy and postpartum: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2012; 97(8): 2543–2565.
- Lazarus J, Brown R, Daumerie C, et al. 2014 European Thyroid Association Guidelines for the Management of Subclinical Hypothyroidism in Pregnancy and in Children. Eur Thyroid J . 2014; 3(2): 76–94.
- Korevaar TIM, Medici M, Visser TJ, et al. Thyroid disease in pregnancy: new insights in diagnosis and clinical management. Nat Rev Endocrinol. 2017; 13(10): 610–622.
- Ray S, Gosh S. Thyroid Disorders and Diabetes Mellitus: Double Trouble. J Diab Res Ther. 2016; 2(1).
- Männistö T, Vääräsmäki M, Pouta A, et al. Thyroid dysfunction and autoantibodies during pregnancy as predictive factors of pregnancy complications and maternal morbidity in later life. J Clin Endocrinol Metab. 2010; 95(3): 1084–1094.
- Rawal S, Tsai MY, Hinkle SN, et al. A Longitudinal Study of Thyroid Markers Across Pregnancy and the Risk of Gestational Diabetes. J Clin Endocrinol Metab. 2018; 103(7): 2447–2456.
- Oguz A, Tuzun D, Sahin M, et al. Frequency of isolated maternal hypothyroxinemia in women with gestational diabetes mellitus in a moderately iodine-deficient area. Gynecol Endocrinol. 2015; 31(10): 792–795.
- Yang Y, Li Q, Wang Q, et al. Thyroid antibodies and gestational diabetes mellitus: a meta-analysis. Fertil Steril. 2015; 104(3): 665–71.e3.
- Agarwal MM, Dhatt GS, Punnose J, et al. Thyroid function abnormalities and antithyroid antibody prevalence in pregnant women at high risk for gestational diabetes mellitus. Gynecol Endocrinol. 2006; 22(5): 261–266.
- Gong LL, Liu He, Liu LH. Relationship between hypothyroidism and the incidence of gestational diabetes: A meta-analysis. Taiwan J Obstet Gynecol. 2016; 55(2): 171–175.
- Maleki N, Tavosi Z. Evaluation of thyroid dysfunction and autoimmunity in gestational diabetes mellitus and its relationship with postpartum thyroiditis. Diabet Med. 2015; 32(2): 206–212.
- Iranparvar M, Ghorbani H, Azami A, et al. Thyroid dysfunction and autoimmunity in pregnant women with gestational diabetes mellitus: a cross-sectional study. Int J Adv Med. 2015: 350–353.
- Velkoska Nakova V, Krstevska B, Dimitrovski Ch, et al. Prevalence of thyroid dysfunction and autoimmunity in pregnant women with gestational diabetes and diabetes type 1. Prilozi. 2010; 31(2): 51–59.
- Vafaeimanesh J, Asgarani F, Bagherzadeh M, et al. Thyroid function in pregnant women with gestational diabetes: Is screening necessary? Thyroid Res Pract. 2015; 12(1): 3.
![](https://journals.viamedica.pl/plugins/generic/popups/images/icons/close.png)