Prevalence of hypothyroidism in infertile women and evaluation of response of treatment for hypothyroidism on infertility

Pooled prevalence of hypothyroidism among Indian females with infertility: A systematic review & meta-analysis

Background & objectives Studies suggest hypothyroidism is responsible for female infertility. This review aimed to determine the pooled prevalence of hypothyroidism in Indian infertile women so that hypothyroidism screening can be initiated, and policies are designed for prevalence reduction. Methods Electronic databases including PubMed, Google Scholar and Cochrane library were searched to obtain the relevant articles. Studies that reported the proportion of hypothyroidism in Indian infertile women were selected. Systematic procedures for study selection and data extraction were followed. Each study was evaluated for quality using the Joanna Briggs institute (JBI) critical appraisal checklist. To pool the effect sizes, a random effects model was utilized. Funnel plot and Egger's test were used to assess publication bias. To quantify heterogeneity among studies, I2 statistics were utilized. Subgroup and meta-regression analyses were used to further investigate the heterogeneity of pooled estimates. The sensitivity analysis done whereby each study was excluded in order to examine the influence of that study in the pooled estimate. A P-value of 0.05 or less was considered statistically significant. Results Out of 198 articles, a total of 20 studies involving 2396 cases met the inclusion criteria. The pooled prevalence of hypothyroidism in women with infertility was 28 per cent [95% confidence interval (CI): 20% to 36%] which was highest in Telangana at 62 per cent (n=1; 95% CI 48% to 74%) and lowest in Karnataka at 14 per cent (n=2; 95% CI: 10% to 18%). Interpretation & conclusions Infertile women have high proportion of hypothyroidism, suggesting that screening programmes during diagnostic workup for infertility may provide optimal care. The result of this meta-analysis will help design guidelines and earmark highest prevalence regions to initiate preventive and diagnostic measures for prevalence reduction in future.

Thyroid dysfunction and female infertility. A comprehensive review

INTRODUCTION

Female infertility is defined as the inability to achieve pregnancy following one year of consistent, unprotected sexual intercourse. Among the various endocrine factors contributing to this complex issue, thyroid dysfunction assumes a pivotal and noteworthy role.

METHODS

A narrative review, encompassing 134 articles up to 2023, was conducted utilizing the PubMed/Medline, EMBASE, and Scielo databases. The primary focus of this review was to investigate the effects of thyroid dysfunction on female infertility.

RESULTS

Thyroid disorders exert a significant influence on folliculogenesis, fertilization, and implantation processes. Thyroid autoimmunity, although associated with diminished ovarian reserve, does not typically necessitate levothyroxine therapy. On the other hand, both subclinical and overt hypothyroidism often require levothyroxine treatment to enhance fertility and optimize obstetric outcomes. Hyperthyroidism warrants prompt intervention due to its heightened risk of miscarriage. Furthermore, thyroid dysfunction exerts notable effects on assisted reproductive technologies, underscoring the importance of achieving euthyroidism prior to ovarian stimulation.

CONCLUSION

Women presenting with thyroid dysfunction must undergo meticulous and individualized assessments since fertility outcomes, whether achieved through natural conception or assisted reproductive technologies, can be significantly influenced by thyroid-related factors.

Subclinical hypothyroidism among infertile women at a tertiary hospital in South-West Nigeria

BACKGROUND

Overt thyroid dysfunction is an accepted cause of female infertility. Its milder form, subclinical hypothyroidism have also been implicated as a contributing factor to disturbed reproductive function.

OBJECTIVE

To determine the contribution of subclinical hypothyroidism (SCH) to the burden of infertility.

METHODOLOGY

This is a cross sectional, comparative study of One hundred and twenty women with primary or secondaryinfertility who presented for evaluation at gynaecological clinic and controls which are clients that came to access Family planning services.

RESULTS

The prevalence of infertility among gynaecological patients seen in the clinic was 38.8% (192/495). The prevalence of SCH among the studied infertile women was 11.7% (7/60) compared with 3.3% (2/60) of the control group (p=0.222). The commonest type of infertility was secondary, 76.7% (46/60). All thestudied infertile women with SCH presented with secondary infertility. There was an observed statistically significant difference in the mean serum TSH (3.19±4.38mIU /L vs 1.60±1.22mIU /L) and FT3, FT4 (0.29±0.074ng/dl vs 0.95±0.16ng/dl and 0.33±0.071ng/dl vs 1.09±0.19ng/dl respectively).

CONCLUSION

Subclinical hypothyroidism was found to be higher among infertile women but this finding was not statistically significant, therefore, the routine screening for SCH among infertile women might be unnecessary.

Evaluation of Reproductive Outcome in Infertile Hypothyroid Women on Thyroxine Therapy

Introduction

Thyroid dysfunction is associated with increased risk of infertility. Serum thyroid stimulating hormone (TSH) screening in all women seeking infertility care is recommended and hypothyroid infertile women should be treated with thyroxine until the preconception serum TSH level is <2.5 mU/l.[1] However, insufficient evidence exist to determine if thyroxine therapy improves fertility in subclinical hypothyroid women who are trying to conceive naturally.

Objectives

The objective is to study the effect of thyroxine therapy on reproductive outcome in infertile women with clinical and subclinical hypothyroidism (SCH).

Materials and Methods

The study is a descriptive cohort study with 72 subjects. Women between 20 and 40 years of age with primary or secondary infertility with hypothyroidism were studied and thyroid profile including free T3, T4, TSH, and thyroid antibodies were done. Thyroxine was given to clinical, subclinical hypothyroid subjects depending on TSH levels such that serum TSH levels are maintained < 2.5 mU/L. Serial thyroid function test was done every 6 weeks until the optimal levels were reached. Once normal TSH levels were reached subjects were followed up for 6 months. Reproductive outcome was analyzed in two groups. Group A included hypothyroid infertile women who conceived and Group B included those who did not conceive following thyroxine therapy.

Results

Thirty-eight out of 72 subjects (54%) conceived during thyroxine treatment (Group A) of which 4 cases had miscarriage. Maximum infertile women in Group A (20/38) conceived between 6 and 12 months (52.6%) of thyroxine therapy. Significant decrease was observed in mean TSH levels over a period of 6 months (P < 0.001). The infertility period until pregnancy in Group A reduced significantly from 5.2 ± 1.8 years to 0.5 ± 0.8 years after thyroxine treatment (P = 0.001).

Conclusion

Thyroxine therapy enhances fertility in infertile women with clinical and SCH.

Update of hypothyroidism and its management in Unani medicine

Hypothyroidism is a clinical syndrome caused by thyroid hormone deficiency due to reduced production, deranged distribution, or lack of effects of thyroid hormone. The prevalence of hypothyroidism in developed countries is around 4-5%, whereas it is about 11% in India, only 2% in the UK, and 4·6% in the USA. It is more common in women than in men. Hypothyroidism has multiple etiologies and manifestations. The most common clinical manifestations are weight gain, loss of hair, cold intolerance, lethargy, constipation, dry skin, and change in voice. The signs and symptoms of hypothyroidism differ with age, gender, severity of condition, and some other factors. The diagnosis is based on clinical history, physical examination and serum level of FT3, FT4, and thyroid-stimulating hormone, imaging studies, procedures, and histological findings. The treatment of choice for hypothyroidism is levothyroxine, however; in this review article, we have discussed the epidemiology, etiology, clinical sign and symptoms, diagnosis, complications, and management of hypothyroidism in modern medicine and a comparative treatment by the Unani system of medicine (USM). In the USM, the main emphasis of the principle of treatment (Usool-e-Ilaj) is to correct the abnormal constitution (Su-e-Mizaj) and alter the six prerequisites for existence (Asbab-e-Sitta Zarooriya) to restore normal health. It is a packaged treatment, that is, different components of treatment are given as a package form which includes different drugs, dosages form, and regimens.

Human immunodeficiency: Extragonadal comorbidities of infertility in women

Introduction

Infertility is mediated by several changes system‐wide. These changes are likely to cause other systems‐related pathologies, such as changes in systemic immune response, particularly inflammatory response can lead to cardiovascular diseases and breast cancer.

Methods

These morbidities can exist immediately or years after the diagnosis of infertility. Therefore, understanding the mechanism is important to move toward therapeutic interventions.

Results

Several extragonadal pathologies are reported due to infertility, as well as, how these might also contribute to reproductive disabilities. Detailed evidence are still not present that can give stronger result.

Conclusion

This review highlights some of the most frequent comorbidities that are seen in infertile women, hence requiring a need for complete clinical screening and care, as well as diagnosis and treatment in early stages.

Phosphodiesterase 8B Polymorphism rs4704397 Is Associated with Infertility in Subclinical Hypothyroid Females: A Case-Control Study

BACKGROUND

Subclinical hypothyroidism (SCH) remains largely unnoticed as a major cause of infertility due to asymptomatic. Polymorphisms of phosphodiesterase 8B gene (PDE8B) have been linked with various diseases, including female infertility. Hence, we aimed to study prevalence of SCH, in infertile females, explore association of PDE8B rs4704397 A/G and rs6885099 G/A polymorphisms with infertility in females suffering from SCH and genotype-phenotype correlation of the polymorphisms with thyroid stimulating hormone (TSH) levels in Gujarat population.

MATERIALS AND METHODS

In this retrospective study, TSH level was estimated from plasma of 230 infertile and 100 control females by enzyme-linked fluorescence immunoassay (ELFA) to find out the prevalence of SCH. Further, based on TSH levels, thyroid function test (TFT) was performed in controls and infertile females with subclinical hypothyroidism (IF-SCH). PDE8B rs4704397 and rs6885099 polymorphisms were genotyped by PCR-RFLP and ARMS-PCR, respectively in 74 controls and 60 IF-SCH females.

RESULTS

We observed i. significantly high prevalence of SCH (32%) in the infertile females, ii. significantly lower frequency of 'G' allele (P=0.006), while the frequency of 'A' allele (P<0.0001) was higher in IFSCH females, compared to the controls, for rs4704397 A/G SNP, iii. no significant difference in the genotype (P=0.214; OR=2.51; CI=0.74-8.42) and the allele frequency (P=0.129; OR=1.51; CI=0.92-2.47) of rs6885099 G/A SNP, iv) low linkage disequilibrium for the polymorphisms, v. significantly higher frequency of 'AA' haplotype (P=0.0001; OR=3.84; CI=1.86-8.01),while the 'GG' haplotype (P=0.0023; OR=0.33; CI=0.16-0.69) was significantly lower in IF-SCH females and vi. no significant difference in the TSH level of IF-SCH females with respect to the genotypes.

CONCLUSION

The present study reports an association of PDE8B rs4704397 polymorphism with infertility in SCH females. The study categorically shows a higher prevalence of SCH in infertile females of Gujarat and advocates the importance of screening for SCH in infertility management.

Expression of proteins related to thyroid hormone function in the uterus is down-regulated at the day of implantation in hypothyroid pregnant rats

Hypothyroidism has been linked to infertility, but the mechanisms underlying infertility-related hypothyroidism have yet to be fully elucidated. Therefore, in this study, effects of hypothyroidism on expression of the proteins related to thyroid hormone function in the uterus, which were thought to play a role implantation, including thyroid hormone receptor (TR), thyroid stimulating hormone receptor (TSHR), retinoic acid receptor (RAR) and extracellular kinase (ERK) were identified. Pregnant female rats were rendered hypothyroid by giving methimazole (MMI), orally. Following hypothyroid induction, rats were grouped into control (non-treated) and received subcutaneous thyroxine at 20, 40, and 80 μg/kg/day for five consecutive days. At Day 6, which is the day of implantation (GD 6), rats were sacrificed and the number of embryo implantation site in the uterus was calculated. Then, uterine horns were harvested and expression of the above proteins and their mRNAs were identified by Western blotting and real-time PCR, respectively. In non-treated hypothyroid pregnant rats, the number of embryo implantation sites decreased as compared to euthyroid and hypothyroid rats receiving thyroxine treatment. Similarly, expression of TRα-1, TRβ-1, TSHR, ERK1/2 and RAR proteins and mRNA in the uterus of non-treated hypothyroid rats also decreased (P < 0.05 when compared to euthyroid and thyroxine-treated hypothyroid rats). In conclusion, downregulated expression of the thyroid hormone related proteins in the uterus at the day of implantation might result in infertility as reported in hypothyroid condition.