Thyroid Function Status and Its Impact on Feto-maternal Outcome in Pregnant Women in Bangladesh: A Hospital-based Cross-sectional Study

Background: Thyroid disorders are common in pregnancy and are associated with adverse pregnancy outcomes. The objective of the present study was to assess thyroid status and its association with adverse maternal and neonatal outcomes in pregnant women in Bangladesh.
Methods: This cross-sectional study was conducted on 252 women with term pregnancy included from the Department of Gynecology and Obstetrics of Bangabandhu Sheikh Mujib Medical University (BSMMU) Hospital from September 2019 to October 2020. Their baseline information was collected by face-to-face interviews using a semi-structured questionnaire and approximately 3 ml of blood was drawn after maintaining all aseptic precautions for FT4, TSH, and anti-thyroid antibody (anti-TPO-Ab and anti-TG-Ab) estimation. All laboratory procedures were performed using an autoanalyzer (ADVIA Centaur CP, manufactured by Siemens Healthcare Diagnostic Inc., USA). To assess the thyroid function status of the newborn, blood was drawn by the heel-prick technique, and TSH was analyzed using the same autoanalyzer.
Results: The mean gestational age of the pregnant women was 38.3 (SD 1.3) weeks. Their mean FT4 and TSH levels were 0.96 (SD 0.1) ng/dL (reference range 0.87–1.54 ng/dL for pregnant women) and 1.8 (SD 1.6) mIU/ml (reference range 0.3-3 mIU/L for pregnant women), respectively. The prevalence of overt hypothyroidism was 3.2%, and subclinical hypothyroidism was 5.2%. None of the pregnant women were diagnosed with overt or subclinical hyperthyroidism. All the women with overt hypothyroidism and almost half of the patients with subclinical hypothyroidism had a positive anti-thyroid antibody status (overall prevalence of positive anti-thyroid antibody was 13%). Adverse maternal and fetal outcomes, such as postpartum hemorrhage, low birth weight, intrauterine growth retardation and neonatal hypothyroidism, were more prevalent among women with overt or subclinical hypothyroidism (p value <0.001).
Conclusion: A substantial number of pregnant women in Bangladesh suffer from subclinical or overt hypothyroidism, which increases their risk of adverse pregnancy outcomes.