The Study of Prevalence and Pattern of Thyroid Disorder in Pregnant Women: A Prospective Study

e-ISSN: 0976-822X, p-ISSN:2961-6042 Available online on http://www.ijcpr.com/ International Journal of Current Pharmaceutical Review and Research 2025; 17(9); 10-14 Ali et al. International Journal of Current Pharmaceutical Review and Research 10 Original Research Article The Study of Prevalence and Pattern of Thyroid Disorder in Pregnant Women: A Prospective Study Sk. Antaz Ali1, Indranil Khatua2, Jamsed Mollah3 1RMO –CT, MBBS, MS (Gynecology and Obstetrics), Department of Gynecology and Obstetrics, Murshidabad Medical College and Hospital, West Bengal 742101 2RMO & CT, MBBS, MS, ENT, Department of ENT & Head Neck Surgery, Nil Ratan Sarkar Medical College and Hospital, Kolkata, West Bengal 700014 3MBBS, MS (General Surgery), Department of General Surgery, Murshidabad Medical College and Hospital, West Bengal 742101 Received: 01-06-2025 / Revised: 16-07-2025 / Accepted: 22-08-2025 Corresponding Author: Dr. Indranil Khatua Conflict of interest: Nil Abstract Introduction: Thyroid disorders are among the most prevalent endocrine abnormalities encountered during pregnancy, posing significant risks to both maternal and fetal health. The physiological changes inherent to pregnancy, such as increased blood volume and altered renal clearance, can influence thyroid function tests, making the diagnosis and management of thyroid dysfunctions particularly challenging. Aims and Objectives: This prospective study aims to assess the prevalence and pattern of thyroid disorders among pregnant women, providing valuable insights that could inform screening strategies and management protocols in clinical practice. Materials and Methods: The present study was a prospective observational study. This Study was conducted from March 2024 to February. Total 60 patients were included in this study. Result: The study of 60 pregnant women revealed that most participants were in the 26–30 years age group (n = 25, 41.7%), with a slightly higher proportion being multigravida (n = 32, 53.3%). The majority of women were euthyroid (n = 40, 66.7%), while hypothyroidism (n = 15, 25%) was more common than hyperthyroidism (n = 5, 8.3%). Subclinical forms of both hypothyroidism (n = 10, 66.7%) and hyperthyroidism (n = 3, 60%) predominated over overt forms. Thyroid dysfunction was more frequently observed in the later stages of pregnancy, whereas euthyroid status was more common in the first trimester, highlighting the importance of monitoring thyroid function throughout gestation. Conclusion: The study demonstrated that a majority of pregnant women maintained normal thyroid function, while a notable proportion exhibited thyroid dysfunction, with hypothyroidism being more common than hyperthyroidism. Keywords: Thyroid disorders, Pregnancy, Hypothyroidism, Hyperthyroidism, Prevalence. This is an Open Access article that uses a funding model which does not charge readers or their institutions for access and distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0) and the Budapest Open Access Initiative (http://www.budapestopenaccessinitiative.org/read), which permit unrestricted use, distribution, and reproduction in any medium, provided original work is properly credited. Introduction Thyroid disorders are among the most prevalent endocrine abnormalities encountered during pregnancy, posing significant risks to both maternal and fetal health. The physiological changes inherent to pregnancy, such as increased blood volume and altered renal clearance, can influence thyroid function tests, making the diagnosis and management of thyroid dysfunctions particularly challenging [1]. Globally, the prevalence of thyroid dysfunction during pregnancy varies widely. In iodine-sufficient regions, overt hypothyroidism affects approximately 0.3% to 0.5% of pregnant women, while subclinical hypothyroidism is more common, with estimates ranging from 2% to 3% [2]. Hyperthyroidism, on the other hand, is less common, occurring in about 0.1% to 0.4% of pregnancies [3]. However, in iodine-deficient areas, the prevalence of hypothyroidism can be significantly higher due to inadequate dietary iodine intake [1,4,5]. In India, studies have reported a wide range of thyroid dysfunction prevalence among pregnant women, from 4.8% to 11% [6]. A study conducted in rural Bengaluru found that 25% of pregnant women had hypothyroidism, with 21% having subclinical hypothyroidism and 4% having overt hypothyroidism [5]. These figures underscore the importance of routine screening for thyroid dysfunction in pregnant women, especially in areas with known iodine deficiency [6,5]. The pattern of thyroid disorders during pregnancy includes both overt and subclinical forms. Subclinical hypothyroidism is characterized by elevated serum International Journal of Current Pharmaceutical Review and Research e-ISSN: 0976-822X, p-ISSN: 2961-6042 Ali et al. International Journal of Current Pharmaceutical Review and Research 11 TSH levels with normal free T4 levels, whereas overt hypothyroidism presents with elevated TSH and low free T4 levels. Subclinical hyperthyroidism is defined by low serum TSH levels with normal free T4 levels, and overt hyperthyroidism is characterized by low TSH and elevated free T4 levels [1,4,7]. The etiology of thyroid dysfunction during pregnancy can be multifactorial. In iodinesufficient regions, autoimmune thyroid diseases, such as Hashimoto's thyroiditis and Graves' disease, are common causes of hypothyroidism and hyperthyroidism, respectively [1]. In contrast, iodine deficiency remains a significant cause of thyroid dysfunction in many parts of the world, including India [1,4]. The impact of thyroid dysfunction during pregnancy on maternal and fetal outcomes is profound. Untreated or inadequately managed hypothyroidism can lead to complications such as preeclampsia, preterm birth, low birth weight, and impaired neurodevelopment in the offspring [8]. Similarly, maternal hyperthyroidism, particularly when associated with Graves' disease, can result in adverse outcomes including preterm birth, fetal tachycardia, and neonatal hyperthyroidism [1,9]. Given the potential risks associated with thyroid dysfunction during pregnancy, early detection and appropriate management are crucial. Routine screening for thyroid dysfunction, especially in high-risk populations, can facilitate timely intervention and improve pregnancy outcomes. This prospective study aims to assess the prevalence and pattern of thyroid disorders among pregnant women, providing valuable insights that could inform screening strategies and management protocols in clinical practice [8, 5,10]. Materials and Methods Study Area: Department of Ear, Nose, and Throat (ENT), Nil RatanSircar Medical College & Hospital (N.R.S. Medical College), Kolkata – 700014, West Bengal, India Study Population: The study population comprised pregnant women over a period of 12 months. All pregnant women in their first or early second trimester who provided informed consent were considered eligible for inclusion. Study Period: From March 2024 to February 2025. Sample Size: 60. Inclusion Criteria • Pregnant women aged 18–40 years. • Gestational age ≤20 weeks at the time of enrollment. • Willingness to provide informed consent and participate in the study procedures. Exclusion Criteria • Known history of thyroid disease currently under treatment. • Women with multiple pregnancies (twins or higher-order gestation). • Women with chronic systemic illnesses such as diabetes mellitus, hypertension, renal disease, or autoimmune disorders that could influence thyroid function. • Women taking medications that may affect thyroid function, including lithium, amiodarone, or corticosteroids. Study Design: This study was a prospective observational study. Statistical Analysis: For statistical analysis, data were initially entered into a Microsoft Excel spreadsheet and then analyzed using SPSS (version 27.0; SPSS Inc., Chicago, IL, USA) and GraphPad Prism (version 5). Numerical variables were summarized using means and standard deviations, while Data were entered into Excel and analyzed using SPSS and GraphPad Prism. Numerical variables were summarized using means and standard deviations, while categorical variables were described with counts and percentages. Twosample t-tests were used to compare independent groups, while paired t-tests accounted for correlations in paired data. Chi-square tests (including Fisher’s exact test for small sample sizes) were used for categorical data comparisons. P-values ≤ 0.05 were considered statistically significant. Result Table 1: Demographic Characteristics of Study Population Characteristic Number (n) Percentage (%) Age (years) 18–25 20 33.3 26–30 25 41.7 31–35 10 16.7 >35 5 8.3 Trimester of Pregnancy First Trimester 15 25 Second Trimester 25 41.7 Third Trimester 20 33.3 Primigravida 28 46.7 Multigravida 32 53.3 International Journal of Current Pharmaceutical Review and Research e-ISSN: 0976-822X, p-ISSN: 2961-6042 Ali et al. International Journal of Current Pharmaceutical Review and Research 12 Table 2: Prevalence of Thyroid Disorders in Pregnant Women Thyroid Status Number (n) Percentage (%) Euthyroid 40 66.7 Hypothyroidism 15 25 Hyperthyroidism 5 8.3 Total 60 100 Table 3: Pattern of Hypothyroidism Type of Hypothyroidism Number (n) Percentage (%) Subclinical Hypothyroidism 10 66.7 Overt Hypothyroidism 5 33.3 Table 4: Pattern of Hyperthyroidism Type of Hyperthyroidism Number (n) Percentage (%) Subclinical Hyperthyroidism 3 60 Overt Hyperthyroidism 2 40 Table 5: Association of Thyroid Disorder with Trimester Trimester Euthyroid (n, %) Hypothyroid (n, %) Hyperthyroid (n, %) Total (n) First Trimester 12 (80) 2 (13.3) 1 (6.7) 15 Second Trimester 18 (72) 5 (20) 2 (8) 25 Third Trimester 10 (50) 8 (40) 2 (10) 20 Total 40 (66.7) 15 (25) 5 (8.3) 60 Figure 1: Prevalence of Thyroid Disorders in Pregnant Women Figure 2: Pattern of Hypothyroidism The study included 60 pregnant women with a mean age of approximately 27 years. The majority of participants were in the 26–30 years age group (41.7%), followed by 18–25 years (33.3%), 31–35 years (16.7%), and >35 years (8.3%). Regarding gestational age, 25% of women were in the first International Journal of Current Pharmaceutical Review and Research e-ISSN: 0976-822X, p-ISSN: 2961-6042 Ali et al. International Journal of Current Pharmaceutical Review and Research 13 trimester, 41.7% in the second trimester, and 33.3% in the third trimester. In terms of parity, 46.7% were primigravida, while 53.3% were multigravida. Among the 60 pregnant women studied, the majority were euthyroid, accounting for 66.7% (n = 40) of participants. Hypothyroidism was observed in 25% (n = 15), while hyperthyroidism was less common, affecting 8.3% (n = 5) of the study population. Among the 15 pregnant women diagnosed with hypothyroidism, subclinical hypothyroidism was the most common type, observed in 66.7% (n = 10) of cases, while overt hypothyroidism was present in 33.3% (n = 5) of the participants. Among the 5 pregnant women diagnosed with hyperthyroidism, subclinical hyperthyroidism was more common, observed in 60% (n = 3) of cases, while overt hyperthyroidism was present in 40% (n = 2) of participants. The distribution of thyroid status varied across trimesters. In the first trimester, 80% (n = 12) of women were euthyroid, 13.3% (n = 2) had hypothyroidism, and 6.7% (n = 1) had hyperthyroidism. In the second trimester, 72% (n = 18) were euthyroid, 20% (n = 5) were hypothyroid, and 8% (n = 2) were hyperthyroid. Among women in the third trimester, euthyroid status was observed in 50% (n = 10), hypothyroidism in 40% (n = 8), and hyperthyroidism in 10% (n = 2). Discussion Our study revealed that thyroid dysfunction is relatively common among pregnant women, with hypothyroidism being more prevalent than hyperthyroidism [11,12]. The pattern of hypothyroidism observed showed a higher prevalence of subclinical hypothyroidism compared to overt hypothyroidism, which is consistent with previous reports [13,14]. Hyperthyroidism was less common in our population, and subclinical hyperthyroidism was more frequent than overt hyperthyroidism, aligning with findings from other studies [15,16]. Regarding the distribution across trimesters, hypothyroidism appeared more frequently in the later stages of pregnancy, while euthyroid status was more common in the early trimesters [17,18]. This trend may be attributed to the increasing thyroid hormone requirements as pregnancy progresses, which can unmask previously subclinical thyroid dysfunction if not properly monitored [19]. These findings underscore the importance of regular thyroid screening throughout pregnancy to optimize maternal and fetal outcomes [20]. Conclusion The study demonstrated that a majority of pregnant women maintained normal thyroid function, while a notable proportion exhibited thyroid dysfunction, with hypothyroidism being more common than hyperthyroidism. Subclinical forms of both hypothyroidism and hyperthyroidism were more prevalent than overt forms. Thyroid abnormalities tended to be more frequent in the later stages of pregnancy, highlighting the importance of early screening and monitoring throughout gestation to optimize maternal and fetal outcomes. Reference 1. National Institutes of Health. Thyroid Disease and Pregnancy. 2025. 2. American Academy of Family Physicians. Thyroid Disease in Pregnancy. Am Fam Physician. 2014;89(4):273-280. 3. American Thyroid Association. Autoimmune Thyroid Disease and Pregnancy. 2025. 4. Infantrisk. Hypothyroidism and Pregnancy. 2025. 5. 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