Table of Contents
ISRN Endocrinology
Volume 2013, Article ID 234031, 6 pages
Clinical Study

A Longitudinal Study of Changes in Thyroid Related Hormones among Pregnant Women Residing in an Iodine Deficient Urban Area

1Centre for Nuclear Medicine (CENUM), P.O. Box 53, Mayo Hospital, Lahore, Pakistan
2Institute of Chemistry, New Campus, University of the Punjab, Lahore, Pakistan

Received 27 June 2013; Accepted 1 September 2013

Academic Editors: C.-H. Anderwald, P. F. Collett-Solberg, T. W. Furlanetto, A. Hishinuma, G. A. Jahn, and B. Larijani

Copyright © 2013 Shan Elahi and Zaib Hussain. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Problem Statement. Thyroid gland in women undergoes functional changes during pregnancy. A few studies have described such changes in pregnant women residing in iodine deficient areas. Objective. To document these changes in pregnant women residing in Lahore, a low iodine intake urban area of Pakistan. Patients and Methods. In 254 pregnant women, data of FT4, FT3, and TSH during the first and subsequent trimesters were obtained and compared with those of 110 nonpregnant women. These hormones were determined in serum by radioimmunoassay (RIA) techniques using commercial kits. Results. Compared to nonpregnant women mean FT4 level was decreased, and FT3 and TSH increased significantly ( ) in pregnant women. A negative correlation of FT4 with TSH was observed in all three trimesters. Serum FT3 was positively correlated with TSH only during the third trimester. As a function of gestation time, FT4 levels progressively decreased, and FT3 and TSH levels increased significantly (one-way ANOVA = 108.2, 17.3, and 44.8, resp.; all ) exhibiting thyroid gland adaptations. Conclusion. Pregnancy is associated with significant alterations in thyroid function due to low iodine intake in women residing in study area. The compensated thyroid function poses a risk of thyroid failure in a number of pregnant women.