Frequency of positive thyroid peroxidase antibody and its related factors during pregnancy in pregnant women referring to the centers under coverage of Shahid Beheshti University of Medical Sciences, 2013-2016

Thyroid peroxidase antibody (TPOAb) is the main risk factor for thyroid dysfunction during pregnancy and can be a marker of these disorders during pregnancy. This study was performed with aim to evaluate the frequency of positive thyroid peroxidase antibody and its related factors during pregnancy. This study is a secondary analysis which was performed based on the data available in prospective population based study of The Tehran Thyroid and Pregnancy Study. This study was performed on 2233 pregnant women (at first trimester of pregnancy) who referred to prenatal care centers under coverage of Shahid Beheshti University of Medical Sciences. Serum concentrations of T4، T-uptake، TSH and TPOAb were measured in pregnant women. Mother age، body mass index، parity، gestational age، individual or family history of thyroid dysfunctions، goiter، diabetes type 1 or other autoimmune disorders، history of infertility، abortion، preterm labor، or stillbirth were selected as probable risk factors. Data analysis was performed using STATA software (version 12). In this study، 214 cases (7. 9%) were TPOAb positive. Based on the logistic regression model، the chance of positive TPOAb in women with individual history of thyroid disease was 4. 48 times (95% CI: 2. 26- 8. 85) higher than those without this history (p <0. 05). No significant relationship was found between other factors (maternal age, BMI, parity, gestational age, thyroid medication, family history of thyroid dysfunction, history of infertility, history of abortion and history of preterm labor) and positive TPOAb (P>0. 05). The history of thyroid disorders is associated with positive TPOAb in pregnant women and this factor can be considered as a risk factor for the detection of thyroid autoimmune disorders