: Hypothyroidism during pregnancy has an adverse effect on both mother and child. The maternal and foetal risk is higher in TPOAb (Thyroid peroxidase antibody) positive women compared to women with negative TPO Ab. The recent ATA (American Thyroid Association) guidelines recommend that pregnant women with TSH (Thyroid Stimulating Hormone) concentration above 2.5mU/L should be evaluated for TPOAb status and LT4(levothyroxine) treatment should be considered with TSH values between 2.5mU/L and 4.0mU/L only when TPOAb status is positive.: All the pregnant women booked in first trimester underwent testing for TSH levels and subsequently for anti TPO Ab if TSH levels were between 2.5-4 mIU/ml. The hospital based prevalence of women with anti TPO Ab positive status was determined. These pregnancies were followed till term and the maternal and foetal complications associated with TPO Ab positive and negative status were compared. Total of 400 pregnant women were included. The hospital prevalence of women with anti TPO antibodies in first trimester of pregnancy with TSH values between 2.5- 4 mIU/ml was found to be 23.5%. Anti TPO antibody positive status was significantly more associated with antenatal complications especially GDM and IUGR as compared to patients with anti TPO antibody negative status (47.8% v/s 23.2%, p value 0.001).: Women with TPO Ab positive status are to be vigilantly monitored for early detection and management of various antenatal complications. Determining anti TPO Ab status helps in avoiding unnecessary treatment of the women with TPO Ab negative status and TSH between 2.5-4mIU/ml.