
Background: Thyroid disorders are among the common endocrine problems in pregnant women. It is now well established that not only overt, but subclinical thyroid dysfunction also has adverse effects on maternal and fetal outcome. There are very few data from India about the prevalence of thyroid dysfunction in pregnancy. Aims and objectives: This study aims to find prevalence of thyroid dysfunction in pregnancy and its impact on obstetrical outcome in Indian population. The study has also an objective of finding the occurrence of subclinical hypothyroidism and overt hypothyroidism. Materials and Methods:1055 pregnant women in first and second trimester were registered. Detailed history and examination was done. Apart from routine obstetrical investigations, thyroid stimulating hormone(TSH) level estimation was done. If TSH level was deranged then free T4 and T3 levels estimation were done. Results: Prevalence of thyroid dysfunction was high in this study, with subclinical hypothyroidism in 13.2 %, hypothyroidism in 20.7%and overt hypothyroidism in 1.4% women in a north Indian tertiary care center. Conclusions: Prevalence of thyroid disorders, especially hypothyroidism (20.7%) and subclinical hypothyroidism (13.2%) was high.