Hypothyroidism and Pregnancy outcome

INTRODUCTION: Thyroid disorders are the second most common endocrinologic disorders in pregnancy. Hypothyroidism is mainly caused by a primary abnormality in the thyroid, although a few cases are caused by hypothalamic dysfunction also. In pregnant or postpartum women, the most common causes are chronic /subacute autoimmune thyroiditis (Hashimoto's thyroiditis), iodine deficiency, radioactive iodine therapy or surgical removal of thyroid gland. Iodine deficiency is the commonest cause. Hashimoto’s thyroiditis is a common cause in industrialized nations. Overt hypothyroidism occurs in 0.3 to 0.5 % and subclinical in 2-3% of patients. Post partum thyroiditis reportedly affects 4-10% of women. AIMS OF THE STUDY: Primary Aim of the Study: To assess the benefits and pregnancy outcome in promptly diagnosed and adequately treated antenatal hypothyroid women. Secondary Aim of the Study: To assess whether unfavourable pregnancy outcome and complications are more among the antenatal women who are diagnosed late in pregnancy and hence inadequately treated. MATERIALS AND METHODS: To measure pregnancy outcomes in all the study subjects, all antenatal women in their first trimester (first booking) or if they have their first visit only in second trimester will be screened with serum TSH. If TSH is more than 3miu/ml, they will be started on treatment after doing an FT4.They will be monitored to see if their treatment is adequate by repeating a serum TSH again in 2nd and 3rd trimesters. These women will be followed up till term and watched for any complications. Finally, they will be analysed to see if there is a significant increase in complications in the antenatal women who were diagnosed and started on treatment late and whether these complications could have been avoided if they were to be started on treatment early in the course of pregnancy Inclusion Criteria: a) All first and second trimester antenatal women with singleton gestation which will include overt hypothyroid women who are already on treatment (who have been informed about the study and who are willing to pay for the blood test). b) Women with subclinical hypothyroidism (elevated TSH, normal fT4). Exclusion Criteria: Multiple gestation. CONCLUSION: Thyroid hormone is essential for early placental development in pregnancy. Especially during the first twelve weeks of pregnancy the fetus entirely depends upon the maternal thyroid hormone for the normal neural and skeletal development. Hence early diagnosis and adequate treatment of maternal hypothyroidism in pregnancy is essential in decreasing the incidence of complications like abortion, pre eclampsia, IUGR, placental abruption, oligohydramnios and low birth weight which are associated with hypothyroidism. Inadequately treated hypothyroid women in my study group had a 3 fold increased risk of developing preeclampsia. There was no significant increase in the incidence of abortion or fetal growth restriction in the inadequately treated group. The incidence of GDM in my study is 10.5%. There was no case of placental abruption in my study group. Oligohydramnios was found to occur more commonly in the inadequately treated group. Adequate treatment significantly reduced certain complications like pre eclampsia