A prospective observational study of thyroid dysfunctions during pregnancy in a tertiary care hospital

Sarojamma Chunchaiah, Nagendra Prasad, Murali B. M., Rupakala B. M., Nagarathnamma Rangaiah


Background: Thyroid dysfunctions are the second most common endocrine disorders seen during pregnancy. Overt or subclinical thyroid dysfunction during pregnancy adversely affects maternal and fetal outcomes. Maternal euthyroid status in early gestation period and optimal transfer of thyroxine to fetus is crucial for the optimal growth, development and maturation of fetal nervous system. This study is undertaken to know the magnitude of thyroid dysfunctions during pregnancy in our region and to validate the need for early detection of maternal thyroid dysfunctions by antenatal screening.

Methods: It was a hospital based prospective study over a period of one year. According to our study criteria, blood samples were collected from consenting pregnant woman during their first antenatal visit and analyzed for TSH level by ultrasensitive method. Free T3 and Free T4 were assayed in patients showing abnormal TSH level and anti thyroid peroxide antibodies tested in all hypothyroid patients. All pregnant woman enrolled were followed up throughout the pregnancy, labour and postpartum to note any maternal and fetal adverse outcomes. The data obtained were analyzed and pregnancy outcomes compared between women showing thyroid dysfunctions and euthyroid state.

Results: Among 800 pregnant women studied 88.75% were euthyroid and 11.25% showed thyroid dysfunction, affecting more in the age group 21-25 years and multigravidae. Prevalence of hypothyroidism was 10.12%, presenting as subclinical hypothyroidism (7.37%) and overt hypothyroidism (2.75%). Hyperthyroidism was seen in 1.12% of cases, 0.87% of them presented subclinically and 0.25% overtly. Risk factor was present in 29.62% of hypothyroid group and 33.33% of hyperthyroid group. Pregnancy complications were seen in 55.55% of thyroid dysfunctional group, preeclampsia being the most common complication.

Conclusions: Our study showed 11.25% prevalence of thyroid dysfunction in pregnant women and commonest dysfunction was hypothyroidism in subclinical form. Adverse pregnancy outcomes were seen in 55.55% woman having thyroid dysfunctions. Absence of risk factor was noted in upto 70% of the cases with thyroid dysfunctions hence the diagnosis will be missed if only high risk cases are screened. Therefore universal screening is recommended early in pregnancy to identify and correct thyroid dysfunctions to prevent the associated adverse pregnancy outcomes.


Adverse pregnancy outcomes, Hypothyroidism, Thyroid dysfunction, Subclinical hypothyroidism, Hyperthyroidism

Full Text:



Sahasrabuddhe A, Pitale S. Screening for thyroid dysfunction during pregnancy. Thyroid Res Pract. 2012;9:15-7.

Unnikrishnan AG, Kalra S. Prevalence of hypothyroidism in adults: an epidemiological study in eight cities of India: Indian J of endocrinology and metabolism. 2013;32(192):397-403.

Pavanaganga A. Observational Study of Subclinical Hypothyroidism in Pregnancy: Indian Journal of Obstetrics and Gynaecology Research. 2015;2(4):255-60.

Shah JM, Mehta MN, Viradia HB. Screening for thyroid dysfunction during pregnancy. Thyroid Res Pract. 2013;10:65-7.

Stagnaro-Green A, Abalovich M, Alexander E. Guidelines of the American Thyroid Association for the diagnosis and management of thyroid disease during pregnancy and postpartum. Thyroid. 2011;21(10)

Lindberg BS, Johansson ED, Nilsson BA. Plasma levels of nonconjugated oestrone, oestradiol-17beta and oestriol during uncomplicated pregnancy: Acta Obstet Gynecol Scand Suppl. 1974;32(0):21-36.

Robbins J, Nelson JH. Thyroxine binding by serum protein in pregnancy and in the newborn: J Clin Invest. 1958 Feb;37(2):153-9.

Haddow JE, Palomaki GE, Allan WC, Williams JR, Knight GJ, Gagnon J. Maternal thyroid deficiency during pregnancy and subsequent neuropsychological development of the child. N Engl J Med. 1999;341:549-55.

Zoeller RT, Rovet J. Timing of thyroid hormone action in the developing brain: Clinical observations and experimental findings. J Neuroendocrinol. 2004;16:809-18.

Casey BM, Dashe JS, Spong CY, McIntire DD, Leveno KJ, Cunningham GF. Perinatal significance of isolated maternal hypothyroxinemia identified in the first half of pregnancy, Obstetrics and Gynecology. 2007;109,5:1129-35.

Negro R. Thyroid insufficiency during pregnancy: complications and implications for screening. Expert Review of Endocrinology and Metabolism. 2008;3,2:137-46.

Joanna K, Burman KD. Levothyroxine Treatment in Pregnancy: indications, efficacy and therapeutic regimen. J of Thyroid Research, 2011. Article ID 843591.

Roti E, Uberti E. Post-partum thyroiditis- a clinical update. Eur J Endocrinol. 2002;146:275-9.

Patil-Sisodia K, Mestman JH. Graves hyperthyroidism and pregnancy: a clinical update, Endocrine Practice. 2010;16,1:118-29.

Lazarus JH, Kaklamanou M. Significance of low thyroid-stimulating hormone in pregnancy, Current Opinion in Endocrinology, Diabetes and Obesity. 2007;14,5:389-92.

Stricker RT, Echenard M, Eberhart R. Evaluation of maternal thyroid function during pregnancy: the importance of using gestational age-specific reference intervals. European Journal of Endocrinology. 2007;157:509-14.

Vaidya B, Anthony S, Bilous M, Shields B, Drury J, Hutchison S, et al. Detection of thyroid dysfunction in early pregnancy: universal screening or targeted high-risk case finding. Journal of Clinical Endocrinology and Metabolism. 2007;92:203-7.

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 Med Screen. 2000;7:127-30.

Sahu MT, Das V, Mittal S. Overt and subclinical thyroid dysfunction among Indian pregnant women and its effect on maternal and fetal outcome: Archieves of gynaecology and obstetrics. 2010 Feb;281(2):215-20.

Casey BM, Dashe JS, Wells CE, McIntire DD, Leveno KJ, Cunningham FG. Subclinical hyperthyroidism and pregnancy outcomes, Obstetrics and Gynecology. 2006;107,2:337-41.

Thammiah J. Screening for thyroid disorders in pregnancy with TSH estimation. Int J Reprod Contracept Obstet Gynecol. 2016;5:1052-5.

Horacek J, Spitalnikova S, Dlabalova B, Malirova E, Vizda J, Svilias I. Universal screening detects two-times more thyroid disorders in early pregnancy than targeted high-risk case finding. Eur J Endocrinol. 2010;163;645-50.

Wang W. The prevalence of thyroid disorders during early pregnancy in China: the benefits of universal screening in the first trimester of pregnancy. European Journal of Endocrinology. 2011 Feb;164(2):263-8.

American College of Obstetricians and Gynecologists. ACOG Practice Bulletin. Clinical management guidelines for obstetrician-gynecologists. Number 37, August 2002. (Replaces Practice Bulletin Number 32, November 2001). Thyroid disease in pregnancy. Obstet Gynecol 2002;100:387-96.

Thung SF, Funai EF, Grobman WA. The cost effectiveness of universal screening in pregnancy for subclinical hypothyroidism, American Journal of Obstetrics and Gynecology. 2009;200(3):267-e1.

Dosiou C, Sanders GD, Araki SS, Crapo LM. Screening pregnant women for autoimmune thyroid disease: a cost-effectiveness analysis, European Journal of Endocrinology. 2008;158(6):841-51.

Lazarus J. Outcome of the controlled antenatal thyroid screening study. Endocrine Abstracts. 2012;29:S52.1.

Lazarus JH. Screening for thyroid dysfunction in pregnancy: Is it worthwhile? J Thyroid Res 2011:397012.

Leung AS, Millar LK, Koonings PP, Montoro M, Mestman JH. Perinatal outcome in hypothyroid pregnancies. Obstet Gynecol. 1993;81:349-53.

Negro R, Schwartz A, Gismondi R, Tinelli A, Mangieri T, Stagnaro-Green A. Universal screening versus case finding for detection and treatment of thyroid hormonal dysfunction during pregnancy. J Clin Endocrinol Metab. 2010;95:1699-1707.

Ashoor G, Maiz N, Rotas M, Jawdat F, Nicolaides KH. Maternal thyroid function at 11 to 13 weeks of gestation and subsequent fetal death. Thyroid. 2010;20:989-93.

Wilson, Karen, Casey. Subclinical thyroid disease and the incidence of hypertension in pregnancy. Obstetrics Gynecology Journal. 2012;119:315-20.

Rana R, Joshi K. Screening of pregnant women for Iodine deficiency and Iron deficiency during early gestation in Vadodara.

Ravanbond M, Kamya. Treatment of iron deficiency anaemia in patients with subclinical hypothyroidism. The American journal of Medicine. 2014;126(5):420-4.

Karakosta P, Alegakis D. Thyroid dysfunction and autoantibodies in early pregnancy are associated with increased risk of gestational diabetes and adverse birth outcomes: J clinical endocrinology metabolism. 2012 Dec; 97(12):4464-72.

Lambadiari V, Mitrou P, Maratou E, Raptis AE, Tountas N, Raptis, SA, et al. Thyroid hormones are positively associated with insulin resistance early in the development of type 2 diabetes: Endocrine. 2011;39:28-32.