Is routine screening of thyroid function in pregnancy justified in an Indian scenario?

Abstract

Background: Maternal thyroid dysfunction in early pregnancy is associated with an adverse maternal and perinatal outcome. Limited data are available on the prevalence of and maternal and foetal morbidities associated with maternal thyroid dysfunction in the Indian setting. Objectives: The aim is to study the prevalence of thyroid dysfunction in pregnancy and to evaluate the maternal and perinatal outcomes. Materials and methods: This prospective study was carried out at SGRH, New Delhi on a cohort of 282 consecutive pregnant women attending antenatal clinics from November 2004 to December 2005. The TSH and FT4 serum levels of the study subjects were tested. Women with thyroid dysfunction were categorized as group I and women with no thyroid dysfunction as group II. The cohort was followed till delivery and the maternal and perinatal outcomes were noted. The TSH level of the neonates was tested within 72 hours of delivery. Observations and results: A total of 28 patients of thyroid dysfunction were diagnosed in our cohort, giving a prevalence of 9.9%. Of these, 11 (3.9%) were known cases of hypothyroidism who had been on treatment before conception (pregestational). Seventeen patients (6%) were diagnosed during pregnancy. Of these, 10 (3.5%) were subclinical (raised TSH, normal FT4) and 7 (2.5%) were patients of overt hypothyroidism (raised TSH, low FT4). Women with hypothyroidism were 7 times more likely than normal women to have an abortion (OR 6.943, 95% CI 2.297–20.962). There was no statistical difference in maternal and perinatal outcome. Conclusion: There is a high prevalence of thyroid dysfunction in the north Indian scenario; screening for thyroid dysfunction should, therefore, be a part of the routine investigation protocol during early pregnancy.

Keywords

• thyroid dysfunction
• pregnancy