Factors Determining Thyroid Status in Pregnant Women in Bulgaria

Thyroid dysfunction occurs in 5-18% of pregnant women and is associated with a higher risk of various gynecological and obstetric complications and these differences are due to the specific characteristic of the study population. The aim of the present study is to analyze the population of pregnant women in Bulgaria regarding the main parameters that are relevant to their thyroid status - age, sequence of pregnancy, reproductive problems, family history of thyroid disease, body mass index. Material: We studied 547 pregnant women, mean age 30±5 years. The study was conducted as a cross-sectional multicenter population-based in 10 regions of Bulgaria or a total of 84 settlements. Methods: An individual Questionnaire was completed, determined in a central laboratory with ECLIA method TSH, FT4, TPOAb and ultrasound examination of the cervical region was conducted. Statistical processing of the material was performed using the standard SPSS 13.0 for Windows. Results: TSH levels are negatively correlated with age, P<0.07. The thyroid volume for the group of women with first pregnancy (n-245, 44.8%) is 8.67±2.23 mL, median 8.35 mL, and the thyroid volume in the remaining 302 (55.2%) women with another pregnancy is 9.15±2.85 mL, median 8.96 mL (P<0.01). Reproductive problems were reported in 119 (21.8%) pregnant women, but the correlation with TSH levels was weak, P<0.009. In 25% of women with family history of thyroid pathology there are abnormalities in thyroid function (in 96.4% hypothyroidism and in 3.6% hyperthyroidism). While in euthyroid pregnant women previous obesity was present in 8.6% (30/350), in hypothyroid pregnant women it was found in 12.7% (14/110), P<0.035. In other words, BMI before pregnancy is a significant predictor of hypothyroidism, proven during pregnancy. Conclusion: The preliminary in-depth study and presentation of the characteristics of the studied Bulgarian population of pregnant women is the basis for a proper assessment of the condition of the thyroid gland.