Endocrine Abstracts

Aim: Thyroid disorders are very common in women of reproductive age. The aim of this study was to determine the prevalence of different biological thyroid disorders during gestational diabetes mellitus (GDM).

Methods: This was a retrospective observational study carried out between March and June 2017 in the day hospital of the National Institute of Nutrition. Pregnant women referred for the management of GDM and who have no history of prior thyroid disorders were included. Five forms of thyroid disorders have been identified: Isolated hypothyroxinemia, Overt Hypothyroidism, Subclinical Hypothyroidism, Overt hyperthyroidism and Subclinical hyperthyroidism. Clinical and biochemical data were obtained by review of medical records.

Results: We included 100 pregnant women with a mean age of 32.4±5.3 years. Of them, 4% were in the first, 35% in the second and 61% in the third trimester of pregnancy. Mean gestational age at time of screening for GDM was 22.3±6 weeks. Approximately 47% of pregnant women were euthyroid, 20% were hypothyroid and 4% were hyperthyroid. Isolated hypothyroxinemia was detected at 29% of women. Hypothyroidism, defined as an elevated TSH level above the trimester-specific reference range, was associated with a decreased level of free T4 (overt hypothyroidism) in 16% and with a normal level of circulating free T4 in 4% of the population (subclinical hypothyroidism). The incidence of overt and subclinical hyperthyroidism in pregnant women was around 1% and 3%, respectively.The presence of thyroid disorders was noted in 40% of pregnant women during the first trimester, in 53% of pregnant women during the 2nd trimester and in 54% during the 3rd trimester.

Conclusion: Our results showed that thyroid disorders are common in our study population. A reassessment of the iodine status of Tunisian women is interesting to detect a possible deficit and therefore introduce targeted supplementation.