High prevalence of subclinical hypothyroidism during first trimester of pregnancy in North India

Levothyroxine for subclinical hypothyroidism during pregnancy: an updated systematic review and meta-analysis of randomized controlled trials

PURPOSE

We aimed to perform a systematic review and meta-analysis addressing the efficacy of levothyroxine therapy in pregnant women with subclinical hypothyroidism considering most recent evidence and subgroups of interest for clinical practice.

METHODS

PubMed, Embase, and Cochrane Central were searched from inception for randomized controlled trials (RCTs) comparing levothyroxine with placebo or no intervention in pregnant women with subclinical hypothyroidism. We used a random-effects model and conducted subgroup analyses based on thyroid peroxidase antibody status, thyroid stimulating hormone levels, fertility treatment, and recurrent miscarriage.

RESULTS

We included 11 RCTs comprising 2,749 pregnant women with subclinical hypothyroidism. Patients treated with levothyroxine (1,439; 52.3%) had significantly lower risk of pregnancy loss (risk ratio 0.69; 95% confidence interval 0.52-0.91; p < 0.01; 6 studies). However, there was no significant association between levothyroxine and live birth (risk ratio 1.01; 95% confidence interval 0.99-1.03; p = 0.29; 8 studies). No statistically significant interaction was observed across subgroups (p > 0.05).

CONCLUSION

Levothyroxine replacement therapy for subclinical hypothyroidism during pregnancy may decrease pregnancy loss when early prescribed. Nevertheless, further investigation is needed in patients with thyroid stimulating hormone above four milliunits per liter, especially when associated with recurrent miscarriage or infertility.

Effects of treating subclinical hypothyroidism in pregnancy in India: Are we treating too many for little gain? A retrospective cohort study

OBJECTIVE

To assess the impact of treatment of subclinical hypothyroidism (SCH) on short-term pregnancy outcomes.

METHOD

Data from 4526 consecutive women with singleton pregnancies who delivered between January 2015 and December 2017 were analyzed. SCH was defined as a thyroid-stimulating hormone (TSH) level between 2.5 and 10 mU/mL with normal free thyroxine. Of those with SCH, some were treated but others were not. These two groups were compared using χ2 and Student t tests for categorical and continuous variables, respectively. Multiple logistic regression models, adjusted for maternal age, body mass index, parity, gestation at TSH measurement, and gestational diabetes mellitus status, were used to investigate the effect of treatment on pregnancy and neonatal outcomes.

RESULTS

In all, 1227 (27.1%) of 4526 women had SCH, of whom 393 (32.0%) were treated. The mean age and body mass index were similar in both groups. The mean gestation at measuring of TSH was 11.7 ± 6.5 weeks. There was no significant difference in pregnancy or neonatal outcomes between the two groups. A sub-group analysis when SCH was defined as TSH 4.0 mU/mL or greater showed a higher rate of large for gestational age and lower rates of low birth weight and small for gestational age in the treated group.

CONCLUSIONS

The prevalence of SCH based on the international guidelines threshold is high in India. Treatment of SCH did not show any difference in pregnancy and neonatal outcomes in this study.

Patterns of Medication Use and Their Determinants in Pregnancy among Women Admitted to the Obstetrics Wards of a Tertiary Care Hospital: A Cross-Sectional Study: Patterns of Medication Use and Their Determinants in Pregnancy

Background

To assess the patterns and factors affecting medication use during antenatal and perinatal periods and to examine maternal and fetal outcomes among pregnant women admitted to a tertiary care hospital in a developing country.

Methods

A cross-sectional study was conducted in the obstetrics wards from 2017 to 2019. Data on patient demographics, co-existent medical conditions, medications, and patient outcomes were collected. Descriptive statistics were used to analyze baseline data, chi-square test was used for categorical variables, and multivariate logistic regression was used for factors influencing drug prescription.

Results

Out of 442 pregnant women, 56% were primigravida with a mean age of 24.7 ± 3.9 years. Approximately 32% experienced at least one disease condition during pregnancy; hypothyroidism (9.7%) was the commonest. The mean number of medications was 2.7 and 38.9% received drugs for a disease condition. Antimicrobials (24.5%) were the commonest drug class. Maternal age of over 25 [(OR (CI): 1.508 (1.191–2.716) ( p = .005)] and maternal illness [OR (CI) 2.934 (1.8–4.7) ( p = .00)] were identified as factors affecting drug prescription. Approximately 39.8% of deliveries were cesarean. Of the newborns, 12.6% had low birth weight, 9.2% were admitted to the newborn intensive care unit, and 14.9% were premature.

Conclusions

Most patients were primigravida and under 25 years. Antimicrobials were the most prescribed drug class. Maternal age over 25 years and maternal illness were identified as the factors affecting medication use. The prevalence of cesareans and prematurity was similar to previous studies.

Clinico-epidemiological profile of women with high-risk pregnancy utilizing antenatal services in a rural primary health center in India

Objective: Early detection and effective management of high-risk pregnancies can substantially contribute to the reduction of adverse maternal and fetal outcomes. This study aimed to determine the prevalence and clinical profile of women with high-risk pregnancies in rural areas who utilize antenatal services in a primary health center (PHC). Materials and Methods: A retrospective analysis was carried out over a six-month period by reviewing the mother and child protection cards maintained at the PHC's Maternal and Child Health Center. During the study period, 950 pregnant women were registered, of whom 793 were included in the study based on the completeness of the records. Data analysis was performed using the licensed Statistical Package for the Social Sciences (SPSS) software version 21.0. Results: The prevalence of high-risk pregnancy among the antenatal women was 272 (34.3%) with 95% CI [31.1-37.7]. Of the 272 women, 240 (88.2%) had a single high-risk factor, while 32 (11.8%) had more than one high-risk factor. The major factor contributing to high-risk pregnancy was hypothyroidism (43.7% with 95% CI [37.9-49.6]), followed by a previous lower segment Caesarean section (LSCS) (19.1%). Conclusion: The study found that the prevalence of high-risk pregnancies was 34.3% in this rural setting. The majority of high-risk pregnancies were due to hypothyroidism, followed by more than one previous LSCS or abortion. Further research is required to track high-risk pregnancy outcomes and investigate the newborn thyroid profile of women with hypothyroidism.

Gestational Diabetes Mellitus with autoimmune subclinical hypothyroidism in pregnancy in relation to gravida

Introduction

Gestational diabetes mellitus (GDM) and hypothyroidism are the most common endocrinological abnormalities associated with pregnancy. The association of gravida with incidence of autoimmune subclinical hypothyroidism (SCH) and GDM in pregnancy has not been studied extensively with availability of very limited data in this context. So, this study was done to find out the association between GDM and autoimmune SCH in pregnancy as per gravida status of the study population.

Materials and Methods

382 antenatal cases, both primi and multigravida, were screened for thyroid dysfunction and GDM in their first ANC coming to a tertiary level health care institution. 75 gm GCT was used for diagnosis of GDM and serum TSH, fT4, and anti-TPO antibody were measured for assessment of thyroid dysfunction. Prevalence of SCH was evaluated taking the ATA 2011 guidelines. Data obtained was also compared with ATA 2017 recommendations. Anti-TPO antibody level more than 60 U/L was considered to be raised value.

Observation

The percentage of GDM was higher in autoimmune SCH participants compared to euthyroid cases with raised anti-TPO Ab Titer. GDM, SCH, and raised anti-TPO Ab titer were overall more prevalent in multigravida cases compared to primigravida participants.

Conclusion

GDM and SCH with high anti-TPO Ab titer were more prevalent in multigravida participants compared to primigravida cases though not statistically significant. As occurrence of SCH varies with nutritional and geographical factors, hence internal trimester specific range should be calculated and used in practice as recommended by ATA 2017 guidelines.

Prevalence of Subclinical Hypothyroidism in Pregnancy and Its Association With Anti-thyroperoxidase Antibody and the Occurrence of Gestational Diabetes Mellitus

Introduction Subclinical hypothyroidism (SCH) and gestational diabetes mellitus (GDM) are common endocrinological abnormalities associated with pregnancy. The presence of a raised anti-thyroperoxidase (anti-TPO) antibody titer increases the risk of progression of subclinical hypothyroidism to overt hypothyroidism. Subclinical hypothyroidism and GDM are known to affect maternal and fetal outcomes adversely. A few studies have shown an increased risk of GDM with autoimmune hypothyroidism. However, data regarding this association between GDM, SCH, and anti-TPO Ab are scarce. This study aimed to find the prevalence of autoimmune subclinical hypothyroidism and its association with GDM in pregnancy. Materials and methods In a cross-sectional study, 382 pregnant women at their first antenatal checkup (ANC) were enrolled in the study. Serum thyroid-stimulating hormone (TSH), free T4 (FT4), anti-TPO Ab, and the 75 g oral glucose tolerance test (OGTT) were evaluated. The results obtained were analyzed in Systat Version 13.2 (SPSS Inc., Chicago, IL). Observations Results showed an SCH prevalence of 37.69% with a raised anti-TPO Ab titer in 49.31% of the diagnosed SCH cases, pointing towards an autoimmune etiology. Our study revealed a GDM prevalence of 12.04%. Out of the 46 GDM cases, 16 were found to have SCH and 3 cases had raised anti-TPO Ab titers. In our study, 27.73% of euthyroid pregnant women had a raised anti-TPO Ab titer. Our study revealed no significant association between GDM, SCH, and raised anti-TPO Ab titer. Conclusion Anti-TPO antibody subsequently leads to hypothyroxinemia, for which it is necessary that cases with high titer of anti-TPO antibody though euthyroid should be meticulously followed up and screened for to detect development of hypothyroidism or SCH, particularly in future pregnancies. However, GDM prevalence was at par with the national figure, but with no significant association of SCH and a high anti-TPO ab titer was found with GDM in our study. Further studies with a larger cohort may establish a causal association between the two most common endocrinological disorders observed in pregnancy.

Can Early Thyroid Profiling Help Avert Spontaneous Abortions/Early Pregnancy Loss: A Retrospective Study

Presence of thyroid autoantibodies in euthyroid women can result in various complications such as miscarriages and pre-eclampsia. Women who are hypothyroid have an increased risk of anaemia, infertility, and preterm birth. Spontaneous miscarriages have been reported in association with women with antithyroid antibodies. This can be utilised as a supplementary marker for the mother's immune system failure. The goal of this study was to compare the thyroid profiles of pregnant women who had a normal delivery to those who had a high-risk obstetric history, and to see if early thyroid profiling can help prevent poor pregnancy outcomes. In conclusion, our analysis has demonstrated that women with abnormal values of T4, T3, anti-thyroid peroxidase (TPO), and TSH were associated with fetal demise when compared to women with normal values of T4, T3, anti-TPO, and TSH. Anti-TPO levels were shown to be elevated in women with a poor obstetric history, making early thyroid profiling improve outcomes in pregnancy. Hypothyroidism with increased TSH and anti-TPO levels may have a negative impact on obstetric history, resulting in the loss of an early pregnancy.

Study on thyroid function test in pregnancy in a tertiary care hospital

Thyroid disorder is a very common endocrine problem encountered by pregnant women. Maternal thyroid dysfunction is associated with adverse outcome both in mother and fetus. The aim of the study: to find out the prevalence of various thyroid disorders in pregnant women attending antenatal clinic. Materials and methods. This prospective cross-sectional study was carried out in the Department of Obstetrics and Gynecology, F.M. Medical College & Hospital, Balasore, Odisha from June 2020 to May 2021. 220 women with uncomplicated singleton pregnancy were included. Serum Thyroid-stimulating hormone (TSH), free T4 (FT4) and free T3 (FT3) were estimated by using electro-chemiluminescence immunoassay technique. Results. Out of 220 pregnant women screened for thyroid dysfunction, 68 were found to have thyroid disorders. 27.3 % of pregnant women had subclinical hypothyroidism, 1.4 % had overt hypothyroidism, 1.8 % had subclinical hyperthyroidism and 0.5 % had overt hyperthyroidism. Prevalence of subclinical hypothyroidism was 6.36 % when the upper reference limit of TSH level taken as 4 mIU/L. Prevalence of thyroid disorder among pregnant women in the age groups 18–25 years, 26–30 years and 31–40 years were 28.9 %, 32.1 % and 38.9 % respectively. There were 35.5 %, 28 % and 26 % pregnant women with thyroid disorders in the first, second and third trimester respectively. Prevalence of both subclinical and overt hypothyroidism were more in multigravida compared to primigravida. Conclusion. Our study revealed high prevalence of thyroid disorders in pregnant women and maternal subclinical hypothyroidism was the most common pattern.

Prevalence of Hypothyroidism in Pregnant Women in India: A Meta-Analysis of Observational Studies

INTRODUCTION

This meta-analysis was conducted to estimate the prevalence of hypothyroidism among pregnant women in India.

METHODS

We searched PubMed, Web of Science, Scopus, Google Scholar, and Shodhganga (Indian thesis repository) for observational studies, providing prevalence of hypothyroidism among pregnant women in India. Systematic study selection and data extraction procedures were followed. Quality assessment of each study was done using JBI critical appraisal checklist. The random effects model was used for pooling the effect sizes. Publication bias was assessed using the funnel plot and rank correlation test. I 2 statistics was used to measure heterogeneity across the studies. Heterogeneity in the pooled estimates was further explored with subgroup analyses and meta-regression analysis.

RESULTS

Sixty-one studies were found eligible and included in this review. The pooled estimate of the prevalence of hypothyroidism in pregnant women was 11.07% (95% CI: 8.79-13.84, I 2 = 99%). Pooled prevalence estimates of subclinical and overt hypothyroidism are 9.51% (95% CI: 7.48-12.04, I 2 = 98%) and 2.74% (95% CI: 2.08-3.58, I 2 = 94%).

CONCLUSION

We documented 11.07% pooled prevalence of hypothyroidism in pregnant women in India.

Characterization of Fetal Thyroid Levels at Delivery among Appalachian Infants

Thyroid disorders are a frequently encountered issue during pregnancy and a cause of maternal and fetal morbidity. In regions like Appalachia that are particularly susceptible to health disparities, descriptive studies are needed to assist in identifying pathologic derangements. We sought to characterize fetal thyroid hormone levels at delivery and investigate whether or not maternal demographic characteristics affect the prevalence of neonatal thyroid disease. A cross-sectional analysis was conducted on 130 pregnant women recruited from the Tri-State region, incorporating areas of Kentucky, Ohio, and West Virginia. Total triiodothyronine (T3) (p = 0.4799), free T3 (p = 0.6323), T3 uptake (p = 0.0926), total thyroxine (T4) (p = 0.8316), free T4 (p = 0.0566), and Thyroid stimulating hormone (TSH) (p = 0.8745) levels were comparable between urban and rural newborns. We found no effect of hypertension status or nicotine levels on fetal umbilical cord thyroid hormone levels. Maternal diabetic status was associated with lower T4 (p = 0.0099) and free T4 (p = 0.0025) levels. Cotinine affected levels of T4 (p = 0.0339). In regard to maternal Body Mass Index (BMI), there was an increase in total T3 as BMI increased (p = 0.0367) and no significant difference in free T3, T3 uptake, T4, free T4, or TSH. There was a negative correlation between TSH and 1 min Apgar scores (p = 0.0058). Lead and cadmium have been implicated to alter TSH levels, but no correlation was found in our study (r² = 0.0277). There were no differences in cord blood between urban (37.3 ± 10.3 fmol/ug DNA) and rural (70.5 ± 26.8 fmol/ug DNA) benzo(a)pyrene DNA adducts (p = 0.174). Thyroid disorders present a unique opportunity for the prevention of perinatal morbidity and mortality, since maternal treatment, as well as maternal demographic characteristics, can have direct fetal effects.

Trimester-Specific Reference Intervals for Thyroid Function Parameters in Indian Pregnant Women during Final Phase of Transition to Iodine Sufficiency

BACKGROUND

Interpretation of thyroid function tests during pregnancy depends on gestational age, method, and population-specific reference intervals. Therefore, there is a worldwide trend to establish trimester-specific levels for different populations. The aim of this study was to establish a trimester-specific reference range for thyroid function parameters during pregnancy in Indian women.

MATERIALS AND METHODS

Thyroid function tests (TSH, FT4, TT4, TT3) of 80, 76, and 73 women at 1^st, 2^nd, and 3^rd trimester, respectively, and 168 nonpregnant women were analyzed after exclusion of low UIC(<150 μg/L) and anti-TPO positivity(>35 IU/ml). Urinary iodine excretion (UIC) was assessed in all. The 2.5^th and 97.5^th percentile values were used to determine the reference ranges for thyrotropin (TSH), free thyroxine (FT4), total thyroxine (TT4), and total triiodothyronine (TT3) for each trimester of pregnancy.

RESULTS

The reference range for TSH for first trimester was 0.19-4.34 μIU/ml, for second trimester 0.46-4.57 μIU/ml, and for third trimester 0.61-4.62 μIU/ml. The reference range during three trimesters for FT4 (ng/dl) was 0.88-1.32, 0.89-1.60, and 0.87-1.54, for total T4 (μg/dl) was 5.9-12.9, 7.4-15.2, and 7.9-14.9. In nonpregnant women, FT4 was 0.83-1.34, total T4 was 5.3-11.8, and TSH was 0.79-4.29. The mean UIC in nonpregnant women was 176 ± 15.7 μg/L suggesting iodine-sufficiency in the cohort.

CONCLUSION

The trimester-specific TSH range in pregnant women in this study is not significantly different from nonpregnant reference range in the final phase of transition to iodine sufficiency in India.

Thyroid Screening During Early Pregnancy and the Need for Trimester Specific Reference Ranges: A Cross-Sectional Study in Lahore, Pakistan

Background

Derangements in thyroid hormone levels can cause multiple complications in the mother and the foetus. Thyroid stimulating hormone (TSH) and free thyroxine (free T4 or FT4) levels are used to screen for maternal thyroid dysfunction; these should be compared with population based trimester-specific reference ranges. Our goal was: to determine the prevalence of various thyroid derangements, in early pregnancy, according to the current reference ranges available; to determine the need for trimester specific reference ranges for the local population.

Methods

A multi-centric, cross sectional population survey was conducted in Lahore, Pakistan. Serum TSH and FT4 levels were measured at the hormone lab of the Pathology department of Combined Military Hospital (CMH) Lahore. The results were entered and analysed using Statistical Package for the Social Sciences (SPSS) version 23. 

Results

In the 293 women sampled, mean FT4 and TSH levels were 15.03 (±5.62) pmol/L and 2.53 (±6.82) mIU/L respectively. According to the laboratory specific reference ranges, the prevalence of overt hyperthyroidism was 4.10%, (mean TSH= 0.03mIU/L); subclinical hyperthyroidism was 16.38%, (mean TSH= 0.17mIU/L); normal 70.65%, (mean TSH = 1.29mIU/L); subclinical hypothyroidism 4.44%, (mean TSH= 15.11mIU/L); overt hypothyroidism 4.44%, (mean TSH = 20.60mIU/L).

Conclusion

Our study showed a significant prevalence of thyroid dysfunction in the first trimester of pregnancy, and therefore highlights the need for more rigorous thyroid screening of women, in early pregnancy. There is a need to monitor these women in order to reduce maternal and foetal complications. Trimester specific reference ranges for thyroid hormones need to be developed in Pakistan.

Differences in Diagnostic Criteria Mask the True Prevalence of Thyroid Disease in Pregnancy: A Systematic Review and Meta-Analysis

BACKGROUND

The reported prevalence of thyroid disease in pregnancy varies widely through the published literature. These discrepancies are due to differences in criteria for euthyroidism, nationality, iodine status, and gestational age at screening. As a result, currently, an accepted rate of prevalence does not exist for the various thyroid diseases in pregnancy. Understanding the true prevalence rates of these disorders has important implications for clinical management and the ongoing discussion regarding universal screening. The aims of this study were to assess (i) the true prevalence of thyroid disorders in pregnancy and (ii) the impact of diagnostic methodology on these rates.

METHODS

A systematic review was conducted of the existing literature, including the Pubmed database and references from relevant review articles. Sixty-three studies reporting prevalence of overt hypothyroidism, subclinical hypothyroidism, isolated hypothyroxinemia, subclinical hyperthyroidism, and overt hyperthyroidism in pregnant women were included. Studies were further classified by thyrotropin (TSH) cutoff for diagnosis in hypothyroid disease and timing of screening for hyperthyroid disease. Meta-analysis yielded pooled prevalence rates, with subgroup analyses for TSH cutoff and timing of screening. Analysis of studies using the 97.5th percentile TSH cutoff was assessed to yield the most accurate prevalence rates for hypothyroidism.

RESULTS

Pooled prevalence rates for hypothyroidism calculated from studies using the 97.5th percentile as an upper limit for TSH were 0.50% for overt hypothyroidism, 3.47% for subclinical hypothyroidism, and 2.05% for isolated hypothyroxinemia. Pooled prevalence rates in the first and second trimesters for hyperthyroidism were 0.91% and 0.65%, respectively, for overt hyperthyroidism and 2.18% and 0.98%, respectively, for subclinical hyperthyroidism.

CONCLUSION

Population-based, trimester-specific TSH cutoffs for diagnosis of hypothyroid disease in pregnancy result in more accurate diagnosis and better estimates for prevalence of disease. Prevalence of hyperthyroidism in pregnancy varies depending on timing of screening. The prevalence rates reported in this study represent the best estimate to date of the true rates of thyroid disease in pregnancy.

Prevalence of Hypothyroidism in Term Pregnancies in North India

BACKGROUND

Hypothyroidism is common in pregnancy. No study has determined the prevalence of hypothyroidism in term pregnancies in India.

AIM

This study aims to determine the prevalence and correlates of hypothyroidism in women who delivered at a center in Karnal, Haryana, North India.

RESULTS

Indoor records of all women who had delivered at this centre from April 2016 to March 2017 were reviewed. The prevalence of hypothyroidism was 12.3%, of which 15.5% were diagnosed during pregnancy. The dose requirement of L-thyroxine ranged from 25 to 200 μg (mean 76.38 +- 43.02). With this, 80% were able to achieve trimester-specific thyroid-stimulating hormone targets. Hypothyroidism did not correlate with any medical or obstetric complications.

CONCLUSION

Hypothyroidism is common in term pregnancies. If treated adequately, healthy fetomaternal outcomes can be achieved.

Postpartum Follow-up in Women Diagnosed with Subclinical Hypothyroidism during Pregnancy

BACKGROUND

Management guidelines about the thyroid disease in pregnancy are silent about the postpartum course of new onset subclinical hypothyroidism (SCH). Hence, we analyzed the 2 years outcome of SCH diagnosed during pregnancy.

MATERIALS AND METHODS

We conducted this retrospective study using the medical records of patients with new onset SCH during pregnancy between 2010 and 2013 (n = 718). Patients who stopped their levothyroxine after delivery with a 2-year follow-up record were included. We excluded patients with known thyroid disorders and continuous use of drugs that affect the thyroid results. The patients were divided into two groups (Group 1 - euthyroid and Group 2 - hypothyroid) based on the final outcome after 2 years. The data were analyzed using appropriate statistical methods and a P < 0.05 was considered statically significant.

RESULTS

A total of 559 (77.8%) women stopped levothyroxine after delivery, and the final follow-up data were available for 467 patients only. At the end of 2 years, 384 (82.2%) remained euthyroid, and the remaining 83 (17.8%) developed hypothyroidism. SCH and overt hypothyroidism were seen in 22 and 61 patients, respectively. Group 2 patients had higher mean age (25.5 vs. 23.6 years), goiter (51 vs. 2%), initial thyroid stimulating hormone (7.9 vs. 5.1 μIU/mL), and thyroid antibody positivity (76 vs. 13%) (P < 0.001).

CONCLUSION

The majority of patients with SCH during pregnancy remain euthyroid after delivery. Advanced age, goiter, positive family history, and thyroid autoimmunity increase the future risk of hypothyroidism in patients with SCH diagnosed during pregnancy.

Urinary iodine and thyroid determinants in pregnancy: a follow up study in Sri Lanka

Background

Iodine deficiency and thyroid dysfunction during pregnancy is associated with number of adverse outcomes that includes mental and physical disabilities creating a huge human and economic burden in later life. Several indicators are used to assess the iodine status of a population: thyroid size by palpation and/or by ultrasonography, urinary iodine excretion and the blood thyroid hormone profile.

Methods

This prospective study was designed to assess the iodine nutrition during the course of pregnancy with reference to urine iodine concentration (UIC) and thyroid determinants among 425 pregnant women from Galle district, Sri Lanka. UIC was estimated in all three trimesters and thyroid functions were assessed in first and third trimesters.

Results

Median (inter-quartile range IQR) UIC was 170.9 (100.0–261.10) μg/L, 123.80 (73.50–189.50) μg/L and 105.95 (67.00–153.50) μg/L in the first, second and third trimesters respectively (p < 0.001). Median thyroid stimulating hormone (TSH) level in the first trimester was 1.30 (0.80–1.80) µIU/mL. This value significantly increased (p < 0.001) to 1.60 (1.20–2.10) µIU/mL at the 3^rd trimester even though it was maintained within the reference range (0.3 – 5.2 µIU/mL). In the assessment of thyroid gland, 67 (16.0 %) women had palpable or visible goitres and 55 (13.1 %) had a goitre that was palpable but not visible. The median thyroid volume of the sample was 5.16 mL (4.30; 6.10 mL) as measured by ultra sound (US) scanning. In multiple regression analysis after controlling for other independent variables (anthropometric, demographic and biochemical parameters); initial body mass index (BMI), goitre size, thyroid volume and parity had significant correlations with the third trimester urinary iodine levels. The thyroid volume accounted for 4.5 % of the urinary iodine variation.

Conclusions

Even though iodine status was progressively worsening with the advancement of pregnancy and iodized salt consumption has not met with the increasing demand for iodine, it was not reflected in the serum TSH level. Therefore, it is worthwhile to assess the long term effects of rising TSH levels and inadequate iodine nutrition during pregnancy on the offspring to prevent even mild iodine deficiency.

Prevalence of hypothyroidism in pregnancy: An epidemiological study from 11 cities in 9 states of India

BACKGROUND

A previous hospital based study from Delhi revealed a high prevalence of hypothyroidism in pregnant women. Several other studies with small sample size also indicate a rising trend of prevalence of hypothyroidism during pregnancy in India.

OBJECTIVE

To assess prevalence of hypothyroidism in pregnant women from various states/cities across India.

MATERIALS AND METHODS

This was a cross-sectional multicenter study conducted at Allahabad (Uttar Pradesh), Bengaluru (Karnataka), Chennai (Tamil Nadu), Kolkata (West Bengal), Hyderabad (Telangana), Nasik (Maharashtra), Rohtak (Haryana), Pune (Maharashtra), New Delhi (Delhi), Srinagar (Kashmir), and Vizag (Andhra Pradesh) enrolling 2599 pregnant women. Estimation of thyroid stimulating hormone (TSH), free T4, and antithyroid peroxidase (TPO) antibodies was carried out using Roche modular kit using ECLIA technology in a central laboratory.

RESULTS

We found in our study population that 13.13% of pregnant women have hypothyroidism (n = 388), using a cutoff TSH level of 4.5 μIU/ml. This prevalence was much higher using the American Thyroid Association criteria. Anti-TPO antibodies were positive in 20.74% of all pregnant women (n = 613), whereas 40% (n = 155) of hypothyroid pregnant women were positive for anti-TPO antibodies.

CONCLUSION

This study concludes that there is a high prevalence of hypothyroidism (13.13%), majority being subclinical in pregnant women during the first trimester from India and universal screening of hypothyroidism may be desirable in our country.

Subclinical hypothyroidism in pregnancy: An emerging problem in Southern West Bengal: A cross-sectional study

Background:

Prevalence of subclinical hypothyroidism (SCH) in pregnancy varies widely in different parts of our country, but it has multiple adverse outcomes in both the mother and fetus.

Objectives:

This study was conducted to evaluate the prevalence of SCH in pregnant women during the first trimester and to identify the prevalence of thyroid autoimmunity in pregnant women.

Materials and Methods:

This cross-sectional study (March 2014 to February 2015) was conducted among the pregnant women attending antenatal clinic in their first trimester at a tertiary care center. Morning samples of study participants were analyzed for free thyroxin (FT4), thyroid stimulating hormone (TSH), and thyroid peroxidase antibody (TPO Ab). Data expressed as mean ± standard deviation and percentage (%) as applicable.

Results:

Of the 510 subjects, 168 had TSH value >2.5 μIU/ml (32.94%) with normal FT4 and they were diagnosed as SCH. TSH level >4.5 μIU/ml was estimated in 13.92% (71) of the subjects. TPO Ab was positive in 57 (33.93%) of subclinical hypothyroid and 5 (1.47%) of normal subjects. 70.42% (50) of the subjects with TSH >4.5 μIU/ml had positive TPO Ab.

Conclusions:

Prevalence of SCH is high in South Bengal and routine thyroid screening at the first antenatal visit should be done to reduce the social and financial burden caused by SCH.

Gestational Age-specific Cut-off Values Are Needed for Diagnosis of Subclinical Hypothyroidism in Early Pregnancy

During the first trimester of pregnancy, thyroid-stimulating hormone (TSH) >2.5 mIU/L has been suggested as the universal criterion for subclinical hypothyroidism. However, TSH levels change continuously during pregnancy, even in the first trimester. Therefore the use of a fixed cut-off value for TSH may result in a different diagnosis rate of subclinical hypothyroidism according to gestational age. The objective of this study was to obtain the normal reference range of TSH during the first trimester in Korean gravida and to determine the diagnosis rate of subclinical hypothyroidism using the fixed cut-off value (TSH >2.5 mIU/L). The study population consisted of pregnant women who were measured for TSH during the first trimester of pregnancy (n=492) and nonpregnant women (n=984). Median concentration of TSH in pregnant women was lower than in non-pregnant women. There was a continuous decrease of median TSH concentration during the first trimester of pregnancy (median TSH concentration: 1.82 mIU/L for 3+0 to 6+6 weeks; 1.53 mIU/L for 7+0 to 7+6 weeks; and 1.05 mIU/L for 8+0 to 13+6 weeks). Using the fixed cut-off value of TSH >2.5 mIU/L, the diagnosis rate of subclinical hypothyroidism decreased significantly according to the gestational age (GA) at TSH (25% in 3+0 to 6+6 weeks, 13% in 7+0 to 7+6 weeks, and 9% for 8+0 to 13+6 weeks, P<0.001), whereas the diagnosis rate was 5% in all GA with the use of a GA-specific cut-off value (P=0.995). Therefore, GA-specific criteria might be more appropriate for the diagnosis of subclinical hypothyroidism.

Feto-maternal Outcome Using New Screening Criteria of Serum TSH for Diagnosing Hypothyroidism in Pregnancy

INTRODUCTION

Evidence suggests that by using the classical non pregnant reference range for serum TSH (STSH), one might miss hypothyroidism in pregnancy. Therefore, upper normal cut off value of S TSH should be taken as <2.5 mIU/L in the first trimester and <3mIU/L in the second and third trimester. However, two Indian studies have reported higher trimester specific reference ranges in the Indian pregnant women.

OBJECTIVES

To assess the maternal and fetal outcomes using new screening criteria with upper S TSH cut off as >3mIU/L, for diagnosing hypothyroidism in pregnancy.

MATERIALS AND METHODS

This study was a cross sectional study, carried out in the Department of Obstetrics and Gynaecology of a tertiary care hospital, in collaboration with the Department of Endocrinology. Pregnant women with ≤ 20 weeks gestation, attending antenatal OPD from December 2010 to January 2012 were included in the study. On the basis of S TSH level, women were divided into Study Group with S TSH level between 3.1 to 6.2 mIU/L, (new range to be studied) and an equal number of age and parity matched Control Group with S TSH levels between 0.4 to 3 mIU/L. The maternal and fetal outcomes were compared between study and control groups.

RESULTS

During the study period, a total of 66 women had S TSH between 3.1-6.2 mIU/L. Maternal and fetal outcomes in both the groups were comparable. There was no difference in the mode of delivery between study and control groups.

CONCLUSION

The lower S TSH cut off recommended for diagnosing hypothyroidism in pregnancy may not be applicable to pregnant Indian women.

Prevalence of thyroid dysfunction among women during the first trimester of pregnancy at a tertiary care hospital in Haryana

BACKGROUND

Undetected and untreated thyroid disorders are associated with adverse maternal and fetal outcomes. There are limited data on the prevalence of newly diagnosed thyroid disease during pregnancy from India. Therefore, this study was designed to evaluate the prevalence of thyroid dysfunction, especially hypothyroidism during the first trimester of pregnancy.

MATERIALS AND METHODS

The present cross-sectional study was conducted at Department of endocrinology and antenatal clinic in the Obstetrics and Gynecology Pt. B.D. Sharma PGIMS, Rohtak over a period of 1-year. The total sample population comprised of 461 pregnant women with uncomplicated intrauterine singleton pregnancies in the first trimester of gestation without any history of thyroid disease or intake of any thyroid medication. Morning blood samples from the participants were analyzed for thyroid function tests, which included FT3, FT4, thyroid-stimulating hormone (TSH) and anti-thyroid peroxidase antibodies (TPO).

RESULTS

A total of 461 women were enrolled for this study. Mean maternal age was 23.79 ± 3.47 years. Median gestational age was 8 weeks 5 days. The median FT3, FT4 and TSH were 3.3 pg/mL, 1.25 ng/dL, and 1.40 mIU/L, respectively. Anti-TPO was elevated in 128 (27.8%) pregnant women. 99 (21.5%) women had sub-clinical hypothyroidism and 39 (39.4%) among them were positive for anti-TPO (P ≤ 0.001). 2 (0.4%) of women had overt hyperthyroidism, whereas 15 (3.3%) of the women had sub-clinical hyperthyroidism.

CONCLUSION

Considering the immense impact that maternal thyroid dysfunction has on maternal and fetal outcomes, prompt identification of thyroid dysfunction and its timely treatment is essential. Thus, universal screening of pregnant women for thyroid dysfunction should be considered especially in a country like India due to the high prevalence of thyroid dysfunction.

Importance of Universal screening for thyroid disorders in first trimester of pregnancy

OBJECTIVE

To determine the importance of screening for Thyriod disorders in the first trimester of pregnancy.

MATERIALS AND METHODS

The Study was conducted on 305 patients which were were randomly selected and screened on OPD basis by TSH levels (cut off level 0.10-2.50 mIU/ml).

RESULTS

In the 305 women screened mean age was 24.46 years, mean gestational age was 9.09 weeks, 89.83% were euthyroid, 9.8%were hypothyroid, 0.32% were hyperthyroid. Incidence of hypothyroidism in high risk population was 20.58% and in normal population was 6.7%. There was significant association of thyroid disorders with high risk factors (P < 0.001). In hypothyroid women 46% had adverse perinatal outcomes and 53.33% had normal outcomes. This shows statistically significant association abnormal TSH values with adverse pregnancy outcomes (P < 0.001). In abnormal perinatal outcomes 6.2% women had Caesarean section out of them 73.68% were euthyroid, 26.31% were hypothyroid 1.9% had preterm labour, out of them 50% were euthyroid, 50% were hypothyroid. Out of 2.2% spontaneous abortions 28.5% were in euthyroid group while 71.4% were in hypothyroid group. There was 1 term stillbirth in hypothyroid group. This study showed significant association between abnormal thyroid stimulating hormone (TSH) values and adverse perinatal outcomes (P < 0.001).

CONCLUSION

There is significant correlation between risk factors and hypothyroidism. So high risk screening is mandatory in early pregnancy. But if we screen only high risk population we would miss 4.6% cases which could have been diagnosed and treated earlier. Therefore it is important to screen all pregnant women in the first trimester, it should be made mandatory.

Subclinical hypothyroidism in the first trimester of pregnancy in North India

Subclinical hypothyroidism based on population and trimester specific cut-offs is reported to complicate 1-2% of all pregnancies. Using the recent Endocrine Society guidelines of 2.5 mIU/L of Thyroid Stimulating Hormone as the upper level of normal in the first trimester the reported prevalence of subclinical hypothyroidism is much higher. Recent publications have also emphasized that there is considerable racial variation in the prevalence of thyroid disorders in pregnancy. Among published literature North Indian women appear to have the highest rates of subclinical hypothyroidism in the first trimester of pregnancy. More widespread use of universal screening and trimester specific ranges in pregnancy for thyroid hormonal assays will lead to a large number of North Indian women requiring treatment for thyroid disorders in pregnancy.