Prevalence of thyroid dysfunction in pregnant women and the need for universal screening: an observational study in Northern Andhra Pradesh population

Krishnamma B., Prabhavathi V., Prasad D. K. V.


Background: The maternal thyroid dysfunction is associated with adverse outcomes such as miscarriage, preterm delivery, preeclampsia, postpartum haemorrhage in mother whereas increased risk of impaired neurological development in foetus. The present study was designed with an aim to determine the prevalence of thyroid dysfunction and the need for universal screening in pregnant women.

Methods: Three hundred and eighty pregnant women between 8-36 weeks of gestation with age group 20-32 years were recruited. Serum free T3, free T4 and TSH levels were assayed by chemiluminescence method. The pregnant women were classified into euthyroid, subclinical hypothyroid (SH), overt hypothyroid (OH) and overt hyperthyroid groups based on the results obtained in the study.

Results: In the present study, the mean ± SD age (in years) and BMI of all pregnant women was 23.9±3.9 and 22.9±1.6 respectively. The maternal age was high in OH and overt hyperthyroid and was statistically significant (p<0.05). Similarly, women with high BMI were prone to OH than normal BMI (p<0.05). The prevalence of thyroid dysfunction was found to be 18.7%. The prevalence of hypothyroidism was 17.4% in which the SH was 13.4% and overt hypothyroidism 3.9%, but overt hyperthyroidism was 1.3%. TSH levels increased with the advancement of gestational age from 2.72±1.85 in first trimester to 3.4±2.05 µIU/mL in third trimester, and the difference was statistically significant (p<0.05). Finally, it was also noticed that the prevalence of raised TSH in high-risk pregnant women was high compared to low-risk women (35.6% vs 5.1%) relative risk (RR) 7.64, 95% confidence interval (CI) 4.62-12.65, (p<0.0001). However, 14 out of 51 (27.5%) with SH were in low-risk group.

Conclusions: The present study states that the prevalence of thyroid dysfunction was 18.7% and also emphasizes the importance of screening all pregnant women for thyroid dysfunction rather than targeted high-risk pregnant women to prevent both maternal and fetal morbidity.


Hypothyroidism, Thyroid dysfunction, Thyroid stimulating hormone, Subclinical hypothyroidism

Full Text:



El Baba KA and Azar ST. Thyroid dysfunction in pregnancy. Int J Gen Med. 2012;5:227-30.

Skjoldebrand L, Brundin J, Carlstrom A. Thyroid associated components in serum during normal pregnancy. Acta Endocrinol. 1982;100(4):504-11.

Boss AM and Kingstone D. Further observations on serum free thyroxine concentrations during pregnancy. Br Med J (Clin res ed). 1981;283(6291):584.

Hopton MR, Ashwell K, Scott IV. Serum free thyroxine concentration and free thyroid hormone indices in normal pregnancy. Clin Endocrinol. 1983;18:431-7.

Nambiar V, Jagtap VS, Sarathi V, Lila AR, Kamalanathan S, Bandgar TR, et al. Prevalence and impact of thyroid disorders on maternal outcome in Asian-Indian pregnant women. J Thyroid Res. 2011;2011:4290-97.

Brain M. Thyroid disease in pregnancy. Obstet Gynecol. 2006;108(5):1283-92.

Reid SM, Middleton P, Cossich MC, Crowther CA, Bain E. Interventions for clinical and subclinical hypothyroidism in pregnancy. Cochrane Database of Systematic Reviews. 2010;7:1-34.

Bona G, Prodam F, Monzani A. "Subclinical hypothyroidism in children: natural history and when to treat". J Clin Res Pediatr Endocrinol. (Review). 2013;5,1(4):23-8.

Chang DLF and Pearce EN. Screening for maternal thyroid dysfunction in pregnancy: A review of the clinical evidence and current guidelines. Journal of Thyroid Research. 2013;2013.

Sahu MT, Das V, Mittal S, Agarwal A, Sahu M. Overt and subclinical thyroid dysfunction among Indian pregnant women and its effect on maternal and fetal outcome. Arch Gynecol Obstet. 2010; 281:215-20.

Stagnaro-Green A. Thyroid antibodies and miscarriage: Where are we at a generation later? J Thyroid Res. 2011;2011:841949.

Mannisto T, Vaarasmaki M, Pouta A, Hartikainen AL, Ruokonen A, Surcel HM, et al. Perinatal outcome of children born to mothers with thyroid dysfunction or antibodies: A prospective population-based cohort study. J Clin Endocrinol Metab. 2009;94:772-9.

Wang W, Teng W, Shan Z, Wang S, Li J, Zhu L, et al. The prevalence of thyroid disorders during early pregnancy in China: The benefits of universal screening in the first trimester of pregnancy. Eur J Endocrinol. 2011;164:263-68.

Rao VR, Lakshmi A, Sadhani MD. Prevalence of hypothyroidismin recurrent pregnant loss in first trimester. Indian J Med Sci. 2008 62(9):357-61.

Casey BM and Leveno KJ. Thyroid disease in pregnancy. Obstet Gynecol. 2006;108:1283-92.

Allan WC, Haddow JE, Palomaki GE, Williams JR, Mitchell ML, Hermos RJ, et al. Maternal thyroid deficiency and pregnancy complications: implications for population screening. J of Med Screen. 2000;7:127-30.

Abalovich M, Gutierrez S, Alcaraz G, Maccallini G, Garcia A, Levalle O. Overt and subclinical hypothyroidism complicating pregnancy. Thyroid. 2002;12:63-8.

Benhadi N, Wiersjnga WM, Reitsma JB, Vrijkotte TG, Bonsel GJ, et al. Higher maternal TSH levels in pregnancy are associated with increased risk for miscarriage, foetal or neonatal death. Eur J of Endocrinol. 2009;160:985-91.

Dhanwal DK, Prasad S, Agarwal AK, et al. High prevalence of subclinical hypothyroidism during first trimester of pregnancy in North India. Indian J Endocrinol Metab. 2013;17:281-84.

Glinoer D. The importance of iodine nutrition during pregnancy. Public Health Nutr. 2007;10(12A):1542-46.

de Escobar GM, Obregon MJ, del Rey FE. Maternal thyroid hormones early in pregnancy and fetal brain development. Best Pract Res Clin Endocrinol Metab. 2004;18:225-48.

Kilby MD. Thyroid hormones and fetal brain development. Clin Endocrinol. 2003;59:280-81.

Morreale EG, Obregon MJ, Escobar RF. Role of thyroid hormone during early brain development. Eur J Endocrinol. 2004;151(Suppl 3):U25-U37.

Ministry of Health and Family Welfare, Government of India; 2011. [accessed on July 1, 2011]. Department of Health and Family Welfare, New Delhi. Annual Report 2010-2011.

Kapil Y, Srivastava R, Badhal S, Palanivel C, Pandav CS, Karmarkar MG. Review of iodine nutrition of pregnant women in India: evidence of significant iodine deficiency. Indian J Med Specialties. 2012;3:49-54.

Kapil U, Singh P, Pathak P. Current Status of Iodine Nutriture and Iodine Content of Salt in Andhra Pradesh. Indian Pediatr. 2004;41:165-69.

Kapil U, Singh P, Dwivedi SN. Ind J of Physiol Pharmacol. 2005;49(1):369-72.

Murray CW, Egan SK, Kim H, Beru N, Bolger PM. US Food and Drug Administration’s Total diet Study: dietary intake of perchlorate and iodine. J Expo Sci Environ Epidemiol. 2008;18(6):571-80.

Dasgupta PK, Liu Y, Dyke JV. Iodine nutrition: iodine content of iodized salt in the United States. Environ Sci Technol. 2008;42(4):1315-23.

Lee SY, Leung AM, He X, Braverman LE, Pearce EN. Iodine content in fast foods:comparison between two fast-food chains in the United States. Endocr Pract. 2010;16(6):1071-72.

Zarghami N, Rohbani-Noubar M, Khosrowbeygi A. Thyroid hormones status during pregnancy in normal Iranian women. Indian J Clin Biochem. 2005;20(2):182-5.

de Groot L, Abalovich M, Alexander EK, et al. Management of thyroid dysfunction during pregnancy and postpartum: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2012;97:2543-65.