Thyroid function tests in euthyroid pregnant and non-pregnant women

Abstract

Background: Pregnancy is associated with significant but reversible changes in thyroid functions, which may exacerbate thyroid disorders or improve thyroid disorders. Objectives: The present study was done to find out changes in thyroid function tests in each trimester in normal pregnant women when compared with non-pregnant women in a tertiary healthcare center. Materials and Methods: A cross-sectional study of 80 euthyroid women in the age group of 16–40 years was done. Twenty were non-pregnant and 20 were from first, second, and third trimesters each. Serum level measurement of T3, T4, and TSH was done with chemiluminescence technique. Results: The results of the study showed a progressive decrease in the mean values of FT3 and FT4, with a significant decrease in FT3 (P-value < 0.0001) and FT4 (P-value =0.0129) only in the third trimester. There was a progressive increase in the mean TSH levels through the pregnancy; however, there was no significant increase when compared with the non-pregnant women. Conclusion: There is a significant increase in serum T3 and T4 in pregnancy. Specific reference intervals should be used to identify the patients at risk and to take early interventions of treatment.