Prevalence of Gestational Auto-immune Thyroid Dysfunction and its Association with Anaemia In A Rural District Of West Bengal

Background: Maternal thyroid dysfunction is associated with risk of obstetric complications and also heralding the risk of abnormal fetal neuro-development. The prevalence and type of thyroid dysfunction in pregnancy varies widely according to ethnicity, demographic and geographical location. Thyroid dysfunction in pregnancy may be associated with autoimmune component too. Anaemia in pregnancy may aggravate with thyroid dysfunction in comparison to euthyroid pregnant subjects. Some epidemiological studies suggested that Iron deficiency anemia may be related to autoimmune thyroid dysfunction in pregnancy. This study aimed to estimate the prevalence of thyroid dysfunction in different trimesters of pregnancy, the association with anemia in pregnancy and whether autoimmunity plays a role in development of thyroid disorder. Methodology: A cross-sectional study was conducted over a period of 1 year in the department of Biochemistry of Bankura Sammilani Medical College. Antenatal mothers attending the antenatal OPD in different trimester were selected depending on predefined inclusion and exclusion criteria. Blood samples were collected for estimation of serum TSH, Free T4, haemoglobin, haematocrit, RBC indices. Serum anti-TPO antibody was estimated only in patients with altered thyroid hormone concentration. Results of the study was compiled, tabulated and analysed using SPSS version 21. Results: 326 pregnant mothers were included as study participants among which 164 were in first trimester and 162 were in second trimester.The prevalence of hypothyroidism among pregnant women was found to be 46.3 % whereas only 1.8% were hyperthyroid.93.3% of the hypothyroid pregnant women had sub-clinical hypothyroidism and the remaining had overt hypothyroidism. 8 subjects out of the total 157 patients with deranged thyroid function were found to be anti-TPO positive. The prevalence of iron deficiency anaemia among hypothyroid mothers were 36.4% in comparison to 33.1 % in non-hypothyroid mothers. Conclusion: Screening of thyroid function status in various stages of gestation is essential because of the high prevalence of hypothyroidism among pregnant women. Estimation of serum anti TPO antibody should be done in all thyroid dysfunctions. Thyroid disorders in pregnancy may be associated with increased severity of iron deficiency anaemia.