Idiopathic Low Ovarian Reserve Is Associated with More Frequent Positive Thyroid Peroxidase Antibodies

Ovarian function measures in normogonadotropic anovulation and subclinical thyroid dysfunction: a prospective cohort study

PURPOSE

To compare ovarian function measures in euthyroid women with normogonadotropic anovulation in subclinical hypothyroidism (SCH) or thyroid autoimmunity (TAI) to those without thyroid dysfunction.

DESIGN

A prospective open-label cohort study analyzed anti-Müllerian hormone (AMH), follicle-stimulating hormone (FSH), luteinizing hormone, estradiol and testosterone concentrations, ovarian volume, and polycystic ovarian morphology (PCOM) incidence between women with and without SCH or TAI in two study arms: polycystic ovary syndrome (PCOS) and hypothalamic-pituitary-ovarian dysfunction (HPOD).

RESULTS

The prevalence of circulating thyroid peroxidase antibodies (TPOAb) was higher in the PCOS compared to the HPOD arm (p = 0.006). No significant differences in the measured parameters were observed based on SCH or TAI status across the entire cohort or individual study arms, except for phenotype D of PCOS, where a greater volume (p = 0.031) and higher incidence of physiological lesions (p = 0.047) in the left ovary were noted in SCH, and phenotype A, where LH concentrations (p = 0.038) were significantly higher in women without TAI. In the PCOS arm, thyroglobulin antibodies (TGAb) concentration correlated negatively with FSH (p = 0.049) and positively with testosterone (p = 0.012) concentrations, while in the HPOD arm, TPOAb and FSH concentrations were negatively correlated (p = 0.028).

CONCLUSIONS

No clinically significant impact of SCH on ovarian function measures was demonstrated. Regarding TAI, significant correlations with still uncertain clinical significance were observed with FSH concentrations, both in PCOS and in HPOD. In view of the obtained results, the benefits of thyroxine supplementation to address menstrual irregularities and improve obstetric outcomes in the examined conditions, require support with clinical evidence.

Prevalence of thyroid autoantibody positivity in women with infertility: a systematic review and meta-analysis

BACKGROUND

Thyroid autoimmunity (TAI) is associated with infertility and complications during pregnancy. However, the prevalence of thyroid autoantibodies in women with infertility remains unclear due to variability in study designs, sample sizes, and populations. In this meta-analysis, we aimed to assess the prevalence of thyroid autoantibodies in women with infertility compared with that in healthy controls.

METHODS

Systematic searches were conducted across PubMed, Embase, Web of Science, and the Cochrane Library from inception to February 5, 2024. The inclusion criteria were women with infertility and those with autoimmune thyroid antibodies. Studies in which relevant data could not be extracted, randomized control trial reports, studies with non-original or duplicate data, and non-English articles were excluded. The main outcome was prevalence rate.

RESULTS

The worldwide pooled prevalence of thyroid autoantibody positivity was 20%. In contrast, a significantly higher TAI prevalence was noted in the population with infertility than in healthy controls (risk ratio [RR] = 1.51). Subgroup analyses indicated that TAI prevalence was higher in patients receiving both assisted reproductive technology (ART) and non-ART treatments than in healthy controls (RR = 1.37 and 3.06, respectively). TAI prevalence was also higher in the recurrent abortion and non-recurrent abortion groups of infertility than in healthy controls (RR = 1.80 and 1.39, respectively). Additionally, a higher TAI prevalence was found in the euthyroid and non-simple euthyroid groups than in the control group (RR = 2.77 and 1.43, respectively). The prevalence was significantly higher in cases of unexplained infertility, endometriosis, ovulation disorders, and fallopian tube factors among women with infertility than among the control group (RR = 1.53, 1.83, 1.42, and 2.00, respectively).

CONCLUSIONS

Thyroid autoantibodies are more prevalent in patients with infertility than in healthy controls. Given the presence of thyroid autoantibodies, screening patients with infertility is clinically important.

Effect and mechanism of Hashimoto thyroiditis on female infertility: A clinical trial, bioinformatics analysis, and experiments-based study

Diagnosing Hashimoto thyroiditis (HT) relies on thyroglobulin antibody (TgAb) and thyroid peroxidase antibody (TPOAb) titers. The influence of these antibodies on female infertility remains a subject of debate. This study aims to explore the effect and mechanism of HT on female infertility. First, a single-center cross-sectional study was conducted to investigate whether TgAb and TPOAb are the key factors leading to female infertility. Second, bioinformatic analysis was performed to investigate the potential target molecules and pathways. Third, in vivo experiments were performed to explore the effects of elevated TgAb levels on embryo implantation in a mouse model of autoimmune thyroiditis (AIT). Four hundred and five infertile women and 155 healthy controls were enrolled in the cross-sectional study. Results indicated that the TPOAb titer was associated with female infertility, while the TgAb titer showed no significant association. The increased levels of TgAb and TPOAb are not significantly correlated with anti-Mullerian hormone. Bioinformatic analysis indicated that the common target molecules for HT and female infertility include interleukin (IL)-6, IL-10, matrix metalloproteinase 9, and tumor necrosis factor, suggesting potential regulation through multiple signaling pathways such as HIF-1, VEGF, MAPK, and Th17 cell differentiation. A certain dose of porcine thyroglobulin can successfully establish a mouse model of AIT. In this mouse model, embryo implantation and ovarian reserve remain unaffected by elevated TgAb levels. In conclusion, the serum TPOAb titer was associated with infertility due to female factors but the TgAb titer showed no significant association. A simple increase in serum TgAb titer does not affect embryo implantation and ovarian reserve in the AIT model.

Subclinical Hypothyroidism and Thyroid Autoimmunity in Pregnancy: To Treat or Not to Treat

Subclinical hypothyroidism and thyroid autoimmunity in pregnancy are common conditions. They are both associated with adverse maternal and offspring outcomes. Women with thyroid autoimmunity should be monitored with regular thyroid function tests preconception and during gestation to identify women who develop hypothyroidism. The effectiveness of thyroid hormone treatment in reducing adverse outcomes in pregnancy has been studied in a number of randomized controlled trials. Current evidence shows obstetrical benefits of levothyroxine treatment in pregnant women with a thyroid-stimulating hormone level greater than 4 mU/L.

Identification of energy metabolism anomalies and serum biomarkers in the progression of premature ovarian failure via extracellular vesicles' proteomic and metabolomic profiles

BACKGROUND

Premature ovarian failure (POF) is a clinical condition characterized by the cessation of ovarian function, leading to infertility. The underlying molecular mechanisms remain unclear, and no predictable biomarkers have been identified. This study aimed to investigate the protein and metabolite contents of serum extracellular vesicles to investigate underlying molecular mechanisms and explore potential biomarkers.

METHODS

This study was conducted on a cohort consisting of 14 POF patients and 16 healthy controls. The extracellular vesicles extracted from the serum of each group were subjected to label-free proteomic and unbiased metabolomic analysis. Differentially expressed proteins and metabolites were annotated. Pathway network clustering was conducted with further correlation analysis. The biomarkers were confirmed by ROC analysis and random forest machine learning.

RESULTS

The proteomic and metabolomic profiles of POF patients and healthy controls were compared. Two subgroups of POF patients, Pre-POF and Pro-POF, were identified based on the proteomic profile, while all patients displayed a distinguishable metabolomic profile. Proteomic analysis suggested that inflammation serves as an early factor contributing to the infertility of POF patients. For the metabolomic analysis, despite the dysfunction of metabolism, oxidative stress and hormone imbalance were other key factors appearing in POF patients. Signaling pathway clustering of proteomic and metabolomic profiles revealed the progression of dysfunctional energy metabolism during the development of POF. Moreover, correlation analysis identified that differentially expressed proteins and metabolites were highly associated, with six of them being selected as potential biomarkers. ROC curve analysis, together with random forest machine learning, suggested that AFM combined with 2-oxoarginine was the best diagnostic biomarker for POF.

CONCLUSIONS

Omics analysis revealed that inflammation, oxidative stress, and hormone imbalance are factors that damage ovarian tissue, but the progressive dysfunction of energy metabolism might be the critical pathogenic pathway contributing to the development of POF. AFM combined with 2-oxoarginine serves as a precise biomarker for clinical POF diagnosis.

Associations between a normal-range free thyroxine concentration and ovarian reserve in infertile women undergoing treatment via assisted reproductive technology

BACKGROUND

Some recent studies have shown that female subclinical hypothyroidism (SCH) is associated with diminished ovarian reserve (DOR). In this study, we aimed to investigate whether serum-free thyroxine (fT4) concentrations within the reference range are associated with ovarian reserve in women.

METHODS

This cross-sectional study included 4933 infertile women with normal-range fT4 concentrations who received assisted reproductive technology treatment in our clinic. The data of women in different fT4 concentration tertiles (namely 12-15.33, 15.34-18.67, and 18.68-22 pmol/L) were compared with ovarian reserve markers, namely the anti-Müllerian hormone (AMH) concentration, the antral follicle count (AFC), and the number of aspirated oocytes. The primary outcomes were the AMH concentration and the risk of DOR, diagnosed as an AMH concentration < 1.1 ng/mL.

RESULTS

The average ages of women in the low-normal, middle-normal, and high-normal fT4 tertiles were 33.20 (standard deviation [SD]: 5.11), 32.33 (SD: 5.13), and 31.61 (SD: 5.10) years, respectively (p < 0.0001). AMH concentrations (adjusted mean: 3.32 [95% confidence interval {CI}: 3.16 to 3.50] vs. 3.51 [3.40 to 3.62] vs. 3.64 [3.50 to 3.80] ng/mL, p = 0.022) were significantly different between the fT4 concentration tertiles. The risk of DOR was significantly increased in the low-normal (adjusted odds ratio: 1.61 [95% CI: 1.01 to 2.58]) and middle-normal (1.47 [95% CI: 1.00 to 2.16]) tertiles compared with the high-normal tertile. Subgroup analysis showed that AMH concentrations were significantly different among the fT4 concentration tertiles in women aged < 35 years (adjusted mean: 3.94 [95% CI: 3.70 to 4.20] vs. 4.25 [4.11 to 4.39] vs. 4.38 [4.18 to 4.58], p = 0.028), whereas this difference was not significant in women aged ≥ 35 years (p = 0.534). The general additive models using fT4 as a continuous variable indicated that a lower fT4 concentration within the normal range was significantly associated with a lower AMH concentration (p = 0.027), a lower AFC (p = 0.018), a lower number of aspirated oocytes (p = 0.001), and a higher risk of DOR (p = 0.007).

CONCLUSION

Low-normal fT4 concentrations are associated with lower ovarian reserve in infertile women.

Impaired embryo development potential associated with thyroid autoimmunity in euthyroid infertile women with diminished ovarian reserve

Purpose

The aim of this study was to evaluate the associations of thyroid autoimmunity (TAI) with the number of oocytes retrieved (NOR), fertilization rate (FR), and embryo quality (EQ) in euthyroid women with infertility and diminished ovarian reserve (DOR).

Methods

This retrospective cohort study involved 1,172 euthyroid women aged 20-40 years with infertility and DOR who underwent an oocyte retrieval cycle. TAI was diagnosed in the presence of serum thyroperoxidase antibody (TPOAb) concentrations higher than 34 IU/ml and/or serum thyroglobulin antibody (TgAb) concentrations exceeding 115.0 IU/ml. Among these women, 147 patients with TAI were classified as the TAI-positive group, while 1,025 patients without TAI were classified as the TAI-negative group. Using generalized linear models (GLMs) adjusted for confounding factors, we evaluated the associations of TAI and the serum TPOAb and TgAb concentrations and NOR, FR, and EQ in this study's subjects. The TPOAb and TGAb values were subjected to log10 transformation to reduce skewness. Logistic regression models were used to estimate the effects of TPOAb and TgAb concentrations on the probabilities of achieving a high NOR (≥7) and high FR (>60%).

Results

For the whole study population, women with TAI had a significantly lower NOR and poorer EQ than women without TAI (P < 0.001 for both). Interestingly, in the TSH ≤2.5 subgroup, the TAI-positive group also had a significantly lower NOR and poorer EQ than the TAI-negative group (P < 0.001 for both). Furthermore, negative associations were observed between log10(TPOAb) concentrations and NOR and the number of high-quality embryos and available embryos (P < 0.05 for all). The log10(TgAb) concentrations were inversely associated with NOR and the number of high-quality embryos (P < 0.05 for all). In the regression analysis, the log10(TPOAb) concentrations had lower probabilities of achieving a high NOR [adjusted odds ratio (aOR): 0.56; 95% confidence interval (95% CI) 0.37, 0.85; P = 0.007].

Conclusions

TAI and higher TPOAb and TgAb concentrations were shown to be associated with reductions in the NOR and EQ in the study population. Our findings provide further evidence to support systematic screening and treatment for TAI in euthyroid women with infertility and DOR.

Intracytoplasmic Sperm Injection Versus In vitro Fertilization in Infertile Women with Thyroid Autoimmunity

Background: It has been reported that intracytoplasmic sperm injection (ICSI) may be the preferred fertilization method for women with thyroid autoimmunity (TAI) seeking assisted reproduction. We compared the reproductive outcomes of women with TAI who were treated with ICSI compared with in vitro fertilization (IVF). Methods: In this retrospective cohort study, we included women with infertility who were referred to the Reproductive Centre of Peking University Third Hospital for their first IVF/ICSI and embryo transfer (ET) treatment cycle from January 2019 to February 2021. In total, 2171 and 743 women with TAI underwent IVF and ICSI, respectively, while 8702 and 2668 women without TAI underwent IVF and ICSI, respectively. We examined the cumulative live birth rate (primary outcome) from the initiated stimulative cycle as well as the secondary outcomes of fertilization rate, rates of clinical pregnancy, and live birth after the first ET cycle. We compared the reproductive outcomes of women treated with IVF and ICSI according to TAI status. Multivariable logistic regression analyses were performed to adjust for relevant confounders. Results: Women who underwent ICSI had significantly higher fertilization rates than those who underwent IVF (median [interquartile range]: 0.6 [0.5-0.8] in the TAI-positive and IVF group vs. 0.7 [0.5-0.8] in the TAI-positive and ICSI group vs. 0.6 [0.5-0.8] the TAI-negative and IVF group vs. 0.7 [0.5-0.8] in the TAI-negative and ICSI group, p < 0.001). However, the rates of cumulative live births, clinical pregnancies, and live births were significantly lower among women with TAI who underwent ICSI than those who underwent IVF (cumulative live birth: 51.8% vs. 47%, adjusted odds ratio [aOR]: 0.80 [confidence interval, CI: 0.67-0.97]; clinical pregnancy: 43.0% vs. 38.8%, aOR: 0.81 [CI: 0.67-0.97]; live birth: 36.2% vs. 32.4%, aOR: 0.81 [CI: 0.66-0.98]). Conclusion: We observed that the use of ICSI in women with TAI was not associated with better assisted reproductive outcomes compared with IVF. Further prospective clinical trials are needed to confirm our findings.

Potential Therapeutic Options for Premature Ovarian Insufficiency: Experimental and Clinical Evidence

Premature ovarian insufficiency (POI) is a condition in which a woman experiences premature decline in ovarian function before the age of 40 years, manifested by menstrual disorders, decreased fertility, and possibly postmenopausal symptoms such as insomnia, hot flashes, and osteoporosis, and is one of the predominant clinical syndromes leading to female infertility. Genetic, immunologic, iatrogenic and other factors, alone or in combination, have been reported to trigger POI, yet the etiology remains unknown in most cases. The main methods currently used clinically to ameliorate menopausal symptoms due to hypoestrogenemia in POI patients are hormone replacement therapy, while the primary methods available to address infertility in POI patients are oocyte donation and cryopreservation techniques, both of which have limitations to some degree. In recent years, researchers have continued to explore more efficient and safe therapies, and have achieved impressive results in preclinical trials. In this article, we will mainly review the three most popular therapies and their related signaling pathways published in the past ten years, with the aim of providing ideas for clinical applications.

Aberrant HPO Axis Alterations and Autoimmune Abnormalities in PCOS Patients with DOR: A Retrospective Analysis

BACKGROUND

There is a group of polycystic ovary syndrome (PCOS) patients in clinic who have diminished ovarian reserve (DOR) in combination. This study was designed to evaluate the differences in glucolipid metabolism, hypothalamic-pituitary-ovarian (HPO) axis-related parameters, and autoimmune antibodies in PCOS patients with and without DOR.

METHODS

A total of 2307 PCOS patients, including 1757 patients with PCOS alone and 550 patients who have both PCOS and DOR, were enrolled in this retrospective study. Parameters of glucolipid metabolism, HPO axis-related parameters, and autoimmune antibodies were measured and analyzed.

RESULTS

The prevalence of DOR among all patients with PCOS was 23.84%. Many HPO axis-related parameters, such as follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E2), and prolactin (PRL) were significantly different in PCOS with DOR compared with PCOS without DOR. The FSH levels were positively correlated with LH, testosterone (T), and androstenedione (AD) levels, but had no association with glucolipid metabolism after adjusting for body mass index (BMI). Moreover, anti-ovarian antibody (AOAb) and anti-21-OH antibody (21-OHAb) levels were significantly elevated in PCOS patients with DOR.

CONCLUSIONS

PCOS patients with DOR showed more chaotic HPO axis hormone levels and elevated autoimmune antibodies, suggesting that autoimmune factors may be the cause of DOR in women with PCOS.

The Thyroid Hormone Axis and Female Reproduction

Thyroid function affects multiple sites of the female hypothalamic-pituitary gonadal (HPG) axis. Disruption of thyroid function has been linked to reproductive dysfunction in women and is associated with menstrual irregularity, infertility, poor pregnancy outcomes, and gynecological conditions such as premature ovarian insufficiency and polycystic ovarian syndrome. Thus, the complex molecular interplay between hormones involved in thyroid and reproductive functions is further compounded by the association of certain common autoimmune states with disorders of the thyroid and the HPG axes. Furthermore, in prepartum and intrapartum states, even relatively minor disruptions have been shown to adversely impact maternal and fetal outcomes, with some differences of opinion in the management of these conditions. In this review, we provide readers with a foundational understanding of the physiology and pathophysiology of thyroid hormone interactions with the female HPG axis. We also share clinical insights into the management of thyroid dysfunction in reproductive-aged women.

Relationship between thyroid antibody levels and ovarian reserve function in infertile chinese women with normal thyroid-stimulating hormone

BACKGROUND

To analyze the relationship of thyroid peroxidase antibody and thyroid globulin antibody levels with ovarian reserve function in infertile women.

METHODS

The data of 721 infertile patients who visited the hospital from January 2019 to September 2022 and whose thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), and free thyroxine (FT4) levels were in the normal range, were retrospectively analyzed. These patients were divided into two sets of three groups-the negative group, the 2.6 IU/ml ~ 100 IU/ml group and the TPOAb > 100 IU/ml group according to the TPOAb (thyroid peroxidase antibody) level, or the TgAb (anti-thyroglobulin antibody) negative group, the 14.58 IU/ml ~ 100 IU/ml group and the TgAb > 100 IU/ml group according to the TgAb level. They were compared for differences in ovarian reserve function index and thyroid hormone levels and analyzed for the relationship among thyroid antibody levels, ovarian reserve function, and thyroid hormone levels.

RESULTS

When TSH > 2.5 mIU/L, the bFSH (basal follicle stimulating hormone) level in the TPOAb > 100 IU/ml group (9.10 ± 1.16 IU/L) was significantly higher than that in the TPOAb negative group (8.12 ± 1.97 IU/L) and the 2.6 IU/ml ~ 100 IU/ml group (7.90 ± 1.48 IU/L) (P < 0.05); when TSH ≤ 2.5 mIU/L, there were no statistically significant differences in the bFSH and AFC (antral follicle count) number at different TPOAb levels. Whether TSH ≤ 2.5 mIU/L or TSH > 2.5 mIU/L, there were no statistically significant differences in the bFSH and AFC number at different TgAb levels (P > 0.05). FT3/FT4 ratio in the TPOAb 2.6 IU/ml ~ 100 IU/ml group and the > 100 IU/ml group was significantly lower than in the negative group. FT3/FT4 ratio in the TgAb 14.58 ~ 100 IU/ml group and the > 100 IU/ml group was also significantly lower than in the TgAb negative group (P < 0.05). TSH level in the TPOAb > 100 IU/ml group was significantly higher than in the 2.6 ~ 100 IU/ml group and the TPOAb negative group, but there were no statistically significant differences among different TgAb groups.

CONCLUSIONS

When TPOAb > 100 IU/ml and TSH > 2.5 mIU/L, it may affect the ovarian reserve function in infertile patients, and the mechanism may be associated with increased TSH and the imbalance of FT3/FT4 ratio caused by the increase of TPOAb.

Impact of Antithyroperoxidase Antibodies (Anti-TPO) on Ovarian Reserve and Early Embryo Development in Assisted Reproductive Technology Cycles

Autoimmune thyroid disease (AITD) is one of the most common endocrinopathies and is more prevalent in women. It becomes evident that the circulating antithyroid antibodies that often follow AITD have effects on many tissues, including ovaries, and therefore that this common morbidity might have an impact on female fertility, the investigation of which is the aim of the present research. Ovarian reserve, ovarian response to stimulation and early embryo development in infertile patients with thyroid autoimmunity were assessed in 45 women with thyroid autoimmunity and 45 age-matched control patients undergoing infertility treatment. It was demonstrated that the presence of anti-thyroid peroxidase antibodies is associated with lower serum anti-Müllerian hormone levels and antral follicle count. Further investigation revealed the higher prevalence of sub-optimal response to ovarian stimulation in TAI-positive women, lower fertilization rate and lower number of high-quality embryos in this group of patients. The cut-off value for follicular fluid anti-thyroid peroxidase antibody affecting the above-mentioned parameters was determined to be 105.0 IU/mL, highlighting the necessity of closer monitoring in couples seeking infertility treatment with ART.

A review of autoimmunity and immune profiles in patients with primary ovarian insufficiency

Primary ovarian insufficiency (POI) is a complicated clinical syndrome characterized by progressive deterioration of ovarian function. Autoimmunity is one of the main pathogenic factors affecting approximately 10% to 55% of POI cases. This review mainly focuses on the role of autoimmunity in the pathophysiology of POI and the potential therapies for autoimmunity-related POI. This review concluded that various markers of ovarian reserve, principally anti-Müllerian hormone, could be negatively affected by autoimmune diseases. The presence of lymphocytic oophoritis, anti-ovarian autoantibodies, and concurrent autoimmune diseases, are the main characteristics of autoimmune POI. T lymphocytes play the most important role in the immune pathogenesis of POI, followed by disorders of other immune cells and the imbalance between pro-inflammatory and anti-inflammatory cytokines. A comprehensive understanding of immune characteristics of patients with autoimmune POI and the underlying mechanisms is essential for novel approaches of treatment and intervention for autoimmune POI.

Impact of Thyroid Autoimmunity on Assisted Reproductive Technology Outcomes and Ovarian Reserve Markers: An Updated Systematic Review and Meta-Analysis

Background: Thyroid autoimmunity (TAI) has a high prevalence among women of reproductive age. Investigating its possible impact on ovarian function and fertility is, thus, of utmost relevance. The aim of this systematic review and meta-analysis was to elucidate the effect of TAI on both assisted reproductive technology (ART) outcomes and ovarian reserve. Methods: This systematic review and meta-analysis was restricted to two groups of research articles investigating the association between TAI and: (1) autologous ART outcomes (i.e., fertilization rate [FR], implantation rate, clinical pregnancy rate [CPR], miscarriage rate, and live birth rate), (2) markers of ovarian reserve (i.e., anti-Müllerian hormone, basal follicle stimulating hormone, antral follicle count, and number of oocytes retrieved). Studies including women affected by overt hypo/hyperthyroidism were excluded. Relevant studies were identified by a systematic search in PubMed, MEDLINE, ClinicalTrials.gov, Embase, and Scopus, from database inception to May 1, 2022. Results: From a total of 432 identified publications, 22 studies were included in Group 1 and 26 studies in Group 2. The presence of TAI was associated with a higher risk of miscarriage (7606 participants, odds ratio [OR] 1.52, confidence interval [CI 1.14-2.01], p = 0.004, I² = 53%), lower chance of embryo implantation (7118 participants, OR 0.72, [CI 0.59-0.88], p = 0.001, I² = 36%), and live birth (11417 participants, OR 0.73, [CI 0.56-0.94], p = 0.02, I² = 71%). These associations were no longer observed in a subgroup analysis of patients who exclusively underwent intracytoplasmic sperm injection (ICSI). The FR and CPR as well as the mean values of surrogate markers of oocyte quantity appeared not to be affected by TAI. Conclusions: This data synthesis suggest a higher risk of adverse ART outcomes in women with positive TAI. However, the reliability of these findings is hampered by the relatively low quality of the evidence and significant heterogeneity in many of the meta-analyses. The possible protective effect of ICSI is promising but should be confirmed in controlled prospective clinical trials. PROSPERO Registration ID: CRD42021236529.

The Impact of Moderately High Preconception Thyrotropin Levels on Ovarian Reserve Among Euthyroid Infertile Women Undergoing Assisted Reproductive Technology

Background: Thyroid dysfunction is prevalent in reproductive-age women and has been identified as a risk factor for female infertility. However, it remains largely unclear whether subtle thyroid dysfunction, as estimated by moderately high thyrotropin (TSH) levels within the normal range, is associated with ovarian reserve in infertile women before assisted reproductive technology (ART) treatment. Methods: This cross-sectional study involved 3501 euthyroid infertile women, including 2189 women with TSH levels ≤2.5 μIU/mL and 1312 women with high-normal TSH levels (2.51-4.20 μIU/mL). Ovarian reserve markers were compared between women with low- and high-normal TSH levels. Correlation analysis and regression models were used to estimate the association of TSH levels with ovarian reserve. In addition, the association of subtle thyroid dysfunction with ovarian reserve was further evaluated after stratification for different infertility diagnoses and statuses of thyroid autoimmunity (TAI). Results: In the total population, women with high-normal TSH levels had significantly decreased anti-Müllerian hormone (AMH) concentrations (p < 0.001), a lower bilateral antral follicle count (AFC) (p < 0.001), and a higher prevalence of diminished ovarian reserve (DOR) (p = 0.018) than women with low-normal TSH levels. The TSH levels showed a negative association with both AMH levels (r = -0.050, p = 0.003) and bilateral AFC (r = -0.071, p < 0.001). Furthermore, the association of high-normal TSH levels with decreased AMH and AFC was more prominent in infertile women with ovulation dysfunction (p = 0.002, p = 0.002), unexplained infertility (p = 0.020, p = 0.028), or negative TAI (both p < 0.001). Conclusions: These data suggested that subtle thyroid dysfunction was associated with DOR in infertile women before ART treatment, which will add evidence that strengthens the systematic screening of TSH levels/TAI in infertile women and will contribute to the discussion of specific TSH cutoff values in predicting ovarian reserve.

Investigation of a derived adverse outcome pathway (AOP) network for endocrine-mediated perturbations

An adverse outcome pathway (AOP) is a compact representation of the available mechanistic information on observed adverse effects upon environmental exposure. Sharing of events across individual AOPs has led to the emergence of AOP networks. Since AOP networks are expected to be functional units of toxicity prediction, there is current interest in their development tailored to specific research question or regulatory problem. To this end, we have developed a detailed workflow to construct an endocrine-relevant AOP (ED-AOP) network based on the existing information available in AOP-Wiki. We propose a cumulative weight of evidence (WoE) score for each ED-AOP based on the WoE scores assigned to key event relationships (KERs) by AOP-Wiki, revealing gaps in AOP development. Connectivity analysis of the ED-AOP network comprising 48 AOPs reveals 7 connected components and 12 isolated AOPs. Subsequently, we apply standard network measures to perform an in-depth analysis of the two largest connected components of the ED-AOP network. Notably, the graph-theoretic analyses led to the identification of important events including points of convergence or divergence in the ED-AOP network. These findings can suggest potential adverse outcomes and facilitate the development of new endpoints or assays for chemical risk assessment. Detailed analysis of the largest component in the ED-AOP network gives insights on the systems-level perturbations caused by endocrine disruption, emergent paths, and stressor-event associations. In sum, the derived ED-AOP network can provide a broader view of the biological events disrupted by endocrine disruption, as well as facilitate better risk assessment of environmental chemicals.

Thyroid Autoimmunity in Female Infertility and Assisted Reproductive Technology Outcome

The regulation of the female reproductive system is one of the most relevant actions of thyroid hormones. Adequate thyroid hormones production is essential for normal menstrual function and fertility as well as for the successful maintenance of pregnancy. The relationship between reproductive failure and thyroid disorders is particularly relevant and attracts attention worldwide. Thyroid autoimmunity (TAI), defined by the presence of circulating antithyroid antibodies targeting thyroid peroxidase (TPOAb) and thyroglobulin (TgAb), is prevalent among women of reproductive age and is the most frequent cause of thyroid dysfunction. Several studies addressed the association between TAI, thyroid function, and fertility as well as pregnancy outcome after spontaneous or assisted conception. Infertility, miscarriages, and fetal-maternal complications are described in overt autoimmune hypothyroidism. More debatable is the role of mild thyroid dysfunction, mainly subclinical hypothyroidism (SCH), and TAI in the absence of thyroid dysfunction in infertility and reproductive outcome. Assisted reproductive technology (ART) has become an integral element of care for infertility. Women with TAI undergoing ART are of particular interest since they carry a higher risk of developing hypothyroidism after the ovarian stimulation but whether TAI, in absence of thyroid dysfunction, adversely affects ART outcome is still controversial. Likewise, the role of levothyroxine (LT4) in improving fertility and the success of ART in euthyroid women with TAI is unclear. This review discusses the role of TAI, in the absence of thyroid dysfunction, in infertility and in ART outcome.

The Role of Cell and Gene Therapies in the Treatment of Infertility in Patients with Thyroid Autoimmunity

There is a rising incidence of infertility worldwide, and many couples experience difficulties conceiving nowadays. Thyroid autoimmunity (TAI) is recognized as one of the major female infertility causes related to a diminished ovarian reserve and potentially impaired oocyte maturation and embryo development, causing adverse pregnancy outcomes. Growing evidence has highlighted its impact on spontaneously achieved pregnancy and pregnancy achieved by in vitro fertilization. Despite the influence of thyroid hormones on the male reproductive system, there is insufficient data on the association between TAI and male infertility. In past years, significant progress has been achieved in cell and gene therapies as emerging treatment options for infertility. Cell therapies utilize living cells to restore healthy tissue microenvironment and homeostasis and usually involve platelet-rich plasma and various stem cells. Using stem cells as therapeutic agents has many advantages, including simple sampling, abundant sources, poor immunogenicity, and elimination of ethical concerns. Mesenchymal Stem Cells (MSCs) represent a heterogeneous fraction of self-renewal, multipotent non-hematopoietic stem cells that display profound immunomodulatory and immunosuppressive features and promising therapeutic effects. Infertility has a genetic component in about half of all cases, although most of its genetic causes are still unknown. Hence, it is essential to identify genes involved in meiosis, DNA repair, ovarian development, steroidogenesis, and folliculogenesis, as well as those involved in spermatogenesis in order to develop potential gene therapies for infertility. Despite advances in therapy approaches such as biological agents, autoimmune disorders remain impossible to cure. Recent research demonstrates the remarkable therapeutic effectiveness of MSCs in a wide array of autoimmune diseases. TAI is one of many autoimmune disorders that can benefit from the use of MSCs, which can be derived from bone marrow and adipose tissue. Cell and gene therapies hold great potential for treating autoimmune conditions, although further research is still needed.

The relationship between thyroid function and ovarian reserve: a prospective cross-sectional study

Background

Thyroid dysfunction can affect fertility and miscarriage risk by affecting the process of follicular growth, embryo development, implantation, and placental formation. It has been suggested that thyroid disorders are associated with ovarian reserve by affecting the follicular process. The aim of the present study was to investigate the relationship between thyroid hormone levels and ovarian reserve.

Methods

Three hundred fourteen women with infertility due to various etiologies were enrolled in this study (172 individuals with Anti-Mullerian hormone (AMH) level ≥ 1.1 ng/ml and 142 individuals with AMH < 1.1 ng/ml). Serum levels of follicle-stimulating hormone (FSH), estradiol (E2) on day 2–4 of menstrual cycles, AMH, Thyroid-stimulating hormone (TSH), and thyroxine (free T4) were evaluated.

Results

In participants with age over 35 years, median TSH level in women with AMH < 1.1 ng/ml was significantly higher than those with AMH ≥1.1 ng/ml (P-value =0.037). There was no significant difference in body mass index (BMI) in patients with age older than 35 years and younger than 35 years sub-groups based on AMH level (P-value = 0.102, and P-value = 0.909 respectively). With one unit increase in TSH level, the odds of having AMH < 1.1 ng/ml increases by 1.25 times or by 25% (P-value =0.017). Receiver operator characteristic (ROC) curve analysis showed a TSH cut-off point of 1.465 mIU/L in participants over 35 years in identifying decreased AMH level.

Conclusion

Our study supports the relationship between TSH level and ovarian reserve so that with an increase in TSH from a certain level is associated with a decrease in ovarian function.

Thyroid autoimmunity is associated with higher risk of premature ovarian insufficiency-a nationwide Health Insurance Research Database study

STUDY QUESTION

Is thyroid autoimmunity associated with a higher risk of low ovarian reserve and POI?

SUMMARY ANSWER

Thyroid autoimmunity significantly increases the risk of POI in women.

WHAT IS KNOWN ALREADY

POI is closely related with autoimmune disease, and according to some studies, thyroid autoimmunity (TAI) may account for diminished ovarian reserve. However, no large-scale cohort study has demonstrated the association between TAI and POI.

STUDY DESIGN, SIZE, DURATION

A longitudinal population-based retrospective cohort study on the National Health Insurance Research Database (NHIRD) was designed. Since 1 March 1995, the National Health Insurance (NHI) programme in Taiwan has included 99.9% of the 23 million population of Taiwan. Patients between 1 January 2000 and 31 December 2012 were eligible for recruitment, and 21 325 subjects were analysed in our study.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Two cohorts, Hashimoto's and Grave's disease, were composed of patients with autoimmune thyroid disease between 20 and 40 years of age. The comparison cohorts consisted of patients in the NHIRD without autoimmune thyroid disease matched by age at a ratio of 1:4 in subject numbers.

MAIN RESULTS AND THE ROLE OF CHANCE

The Hashimoto's disease (HD) cohort, Grave's disease (GD) cohort and two comparison cohorts were followed up until a diagnosis of amenorrhoea, menopausal syndrome, other ovarian failure or infertility due to ovarian failure had been made. Compared statistically with the non-HD cohort, patients with HD exhibited an 89% higher risk of amenorrhoea (95% CI =1.36-2.61). The HD patients exhibited a 2.40-fold higher risk of infertility due to ovarian failure than the non-HD subjects (hazard ratio (HR)=2.40, 95% confidence interval (CI)=1.02-5.68). In comparison with the non-GD cohort, patients with GD exhibited a 68% higher risk of amenorrhoea (95% CI = 1.43-1.98) after adjustment. According to the Kaplan-Meier analysis, the cumulative incidence of amenorrhoea and menopausal syndrome was significantly higher in the TAI groups than in the control groups.

LIMITATIONS, REASONS FOR CAUTION

This is a retrospective study using ICD-9 disease code analysis to determine the statistical association between two diseases.

WIDER IMPLICATIONS OF THE FINDINGS

Given that autoimmune thyroid disease is highly associated with early diminished ovarian reserve or even premature ovarian failure or POI, the options for infertility treatment may be re-directed to more efficient methods in infertile patients diagnosed with the disease. If the ovarian reserve is normal at the time of diagnosis of thyroid autoimmune disease, close follow-up of ovarian reserve may be highly recommended.

STUDY FUNDING/COMPETING INTEREST(S)

This study is supported in part by Taiwan Ministry of Health and Welfare Clinical Trial Center, Grant Number: MOHW109-TDU-B-212-114004. The authors have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

Evaluation of serum anti-Müllerian hormone levels in women with Hashimoto thyroiditis in the reproductive age

Background/aim

Autoimmune thyroid disease in women is associated with subfertility and early pregnancy loss, and patients with primary ovarian insufficiency have a high prevalence of thyroid autoimmune disorders. The aim of this study was to investigate the association between Hashimoto thyroiditis (HT) and ovarian reserve.

Materials and methods

Levels of serum thyroid stimulating hormones, thyroid autoantibodies, and anti-Müllerian hormone (AMH) were measured in women with HT and a healthy control group between 2018 and 2019.

Results

Evaluation was made of 108 premenopausal women with HT, and a control group of 172 healthy females with normal antithyroid antibody levels and thyroid function. Serum AMH levels were determined to be significantly lower in the HT group compared to the control group.

Conclusion

Ovarian reserve evaluated by serum AMH concentration is affected by thyroid autoimmunity independently of antithyroid antibodies type or titers.

Association between thyroid autoimmunity and ovarian reserve in women with hypothyroidism

Background

The ovarian function and therefore the ovarian reserve may be compromised by the pathogenesis of autoimmune diseases of which, Hashimoto’s thyroiditis (HT) is the most common in women of reproductive age. Furthermore, a prolonged reduction in thyroid hormone concentration results in a broad spectrum of reproductive alteration. Previous reports in the literature have been controversial regarding the impact of hypothyroidism and alterations in the ovarian reserve. Thus, this prospective and comparative study aimed to evaluate the association of hypothyroidism with low ovarian reserve.

Materials and Methods

A subset of 27 patients with primary autoimmune hypothyroidism were compared to healthy women. The ovarian reserve was assessed through the anti-Mullerian hormone (AMH) and the antral follicle count (AFC).

Results

Overall, the two groups did not display significant differences in length of their menstrual cycles neither in the AMH serum levels nor the AFC.

Conclusions

No significant alteration was found in the ovarian reserve of women with HT.

Hashimoto's thyroiditis worsens ovaries in polycystic ovary syndrome patients compared to Anti-Müllerian hormone levels

BACKGROUND

The human ovary is the target of autoimmune attack in cases of autoimmune disorders, which can cause ovarian dysfunction. Due to the higher prevalence of Hashimoto's Thyroiditis (HT) in Polycystic Ovary Syndrome (PCOS) patients, we aimed to evaluate ovarian reserve and the effect of autoimmune exposure time on ovarian reserve in PCOS patients with HT by Anti-Müllerian hormone (AMH) levels.

METHODS

Forty-six PCOS patients and 46 PCOS with HT diagnosed patients who are between 18 and 35 years old were recruited for this study. Detailed medical histories were obtained from all participants. Polycystic ovary image was evaluated and antral follicles were counted by transvaginal ultrasound. Modified Ferriman Gallwey score, body mass index, waist/hip ratio of the patients were examined. Hormonal, biochemical profiles and AMH levels of the patients were evaluated during the early follicular phase. The data of both groups were statistically analyzed with SPSS 18.0.

RESULTS

20 (43.5%) patients in the PCOS group were fertile, 8 (17.4%) patients in the PCOS + HT group were fertile, fertility rate was significantly lower in PCOS + HT group. The mean AMH value was 8.8 ± 8.8 in the PCOS + HT group and 12.4 ± 8.1 in the PCOS group and it was significantly lower in the PCOS + HT group (p = 0.043). AMH values were significantly negatively correlated with anti-thyroid peroxidase antibody (anti-TPO) level and the duration of HT. There was a significant positive correlation between the anti-TPO level and the duration of HT. CONCLUSıON: We pointed out that the coexistence of PCOS and HT, two prevalent diseases of reproductive age, further diminished ovarian reserve. More exposure of the ovaries to autoantibodies can cause ovarian destruction, similar to the thyroid gland like HT. Because of all these close relations with PCOS and thyroid dysfunctions, we recommend evaluating both thyroid autoantibodies and hormone levels in PCOS patients at the first visit. Patients with PCOS + HT should be monitored more closely to determine the fertility treatment options and control premature ovarian failure (POF) table.

2021 European Thyroid Association Guideline on Thyroid Disorders prior to and during Assisted Reproduction

Severe thyroid dysfunction may lead to menstrual disorders and subfertility. Fertility problems may persist even after restoring normal thyroid function, and then an assisted reproductive technology (ART) may be a solution. Prior to an ART treatment, ovarian stimulation is performed, leading to high oestradiol levels, which may lead to hypothyroidism in women with thyroid autoimmunity (TAI), necessitating levothyroxine (LT4) supplements before pregnancy. Moreover, women with the polycystic ovarian syndrome and idiopathic subfertility have a higher prevalence of TAI. Women with hypothyroidism treated with LT4 prior to ART should have a serum TSH level <2.5 mIU/L. Subfertile women with hyperthyroidism planning an ART procedure should be informed of the increased risk of maternal and foetal complications, and euthyroidism should be restored and maintained for several months prior to an ART treatment. Fertilisation rates and embryo quality may be impaired in women with TSH >4.0 mIU/L and improved with LT4 therapy. In meta-analyses that mainly included women with TSH levels >4.0 mIU/L, LT4 treatment increased live birth rates, but that was not the case in 2 recent interventional studies in euthyroid women with TAI. The importance of the increased use of intracytoplasmic sperm injection as a type of ART on pregnancy outcomes in women with TAI deserves more investigation. For all of the above reasons, women of subfertile couples should be screened routinely for the presence of thyroid disorders.

Women with Autoimmune Thyroiditis have Lower Reproductive Life Span or Not? A Cross- Sectional Study

Background:

Autoimmune diseases are a main cause of primary ovarian insufficiency. This study was designed to elucidate the relationship between ovarian reserve and anti-thyroid peroxidase antibodies in women of different ages.

Methods:

98 women in a cross-sectional study was conducted at the infertility Center of Shiraz University of Medical Sciences, Hazrate Zeinab Hospital, from September 2018 to March 2019. Women with infertility and thyroid-stimulating hormone (TSH) &gt; 3mIU/L were included in the study with convenience sampling. Data were collected by a form containing demographic characteristics, thyroid hormones, and ovarian reserve data. Participants were categorized based on the negative or positive anti-thyroid peroxidase (anti-TPO) antibodies. According to a pilot sample, and possible dropout of 20%, the sample size was determined to be 49 cases in each group. The results were compared between groups using SPSS, version 22. All statistical comparisons were performed using the t-test, and the data are presented as the mean±SD. P-values less than 0.05 were considered significant.

Results:

49 women were analyzed in each group. There was no significant difference between the groups in the mean age (P=0.42), body mass index (BMI) (P=0.34), duration of infertility (P=0.99), mean prolactin (P=0.66), TSH (P=0.17), thyroxine (T4) (P=0.87) and follicle-stimulating hormone (FSH) levels (P=0.14). Ovarian reserve characteristics: antral follicular count (AFC) and anti-Müllerian hormone (AMH) levels in anti-TPO positive group were 10.61±7.29 and 1.98±2.38, respectively, and AFC and AMH in anti- TPO negative group were 16.46±6.38 and 2.94±2.22, respectively. There were significant differences between the two groups on AFC (P <0.001) and AMH (P=0.04).

Conclusion:

Patients with autoimmune thyroiditis were at higher risk for decreased ovarian reserve. They should consider their lower reproductive life span during their childbearing years.

Anti-Müllerian Hormone and Ovarian Reserve: Update on Assessing Ovarian Function

CONTEXT

Anti-müllerian hormone (AMH) is produced by granulosa cells of small, growing follicles in the ovary. Serum AMH levels strongly correlate with the number of growing follicles, and therefore AMH has received increasing attention as a marker for ovarian reserve. This review summarizes recent findings and limitations in the application of serum AMH in ovarian reserve assessment.

EVIDENCE ACQUISITION

A PubMed search was conducted to find recent literature on the measurements and use of serum AMH as a marker for ovarian reserve.

EVIDENCE SYNTHESIS

Serum AMH levels are measured to assess the "functional ovarian reserve," a term that is preferred over "ovarian reserve," since AMH levels reflect the pool of growing follicles that potentially can ovulate. Serum AMH levels are used in individualized follicle-stimulating hormone dosing protocols and may predict the risk of poor response or ovarian hyperstimulation syndrome but has limited value in predicting ongoing pregnancy. Serum AMH levels are studied to predict natural or disease-related age of menopause. Studies show that the age-dependent decline rates of AMH vary among women. The generalized implementation of serum AMH measurement has also led to an increase in diagnostic assays, including automated assays. However, direct comparison of results remains problematic.

CONCLUSION

Serum AMH remains the preferred ovarian reserve marker. However, the lack of an international standard for AMH limits comparison between AMH assays. Furthermore, little is known about endogenous and exogenous factors that influence serum AMH levels, which limits proper interpretation of AMH values in a clinical setting.

The influence of thyroid autoimmunity on pregnancy outcome in infertile women: a prospective study

Thyroid dysfunction and thyroid autoimmunity (TAI) have been reported to be linked to infertility, pregnancy loss and preterm birth. Infertile women undergoing assisted reproductive technology are recommended to maintain thyroid stimulating hormone (TSH) levels below 2.5 μIU/mL. It is unclear, however, whether levothyroxine (L-T4) treatment decreases the effects of TAI on fertility and pregnancy outcome in infertile women. We therefore aimed to clarify the influence of TAI on pregnancy undergoing L-T4 treatment for hypothyroidism. Prospectively recruited to this study were the 595 infertile women who visited the Utsunomiya Ladies Clinic between January 2013 and December 2015. Five patients with Graves' disease were excluded. Clinical profiles of 590 women were as follows: proportion of SCH = 19.6%, thyroid peroxidase antibody (TPOAb) positivity = 10.4%, and thyroglobulin antibody (TgAb) positivity = 15.1%. Fertility was not affected by any thyroid-associated factors. Regarding pregnancy outcomes, TPOAb titers were significantly higher in women who had miscarriage than in those progressed to delivery (46.4 ± 114.1 vs. 18.9 ± 54.6 IU/mL, p = 0.039), notably in those undergoing intrauterine insemination (p = 0.046) and in vitro fertilization (p = 0.023). Multivariate logistic regression analysis revealed that higher age (odds ratio 26.4, p < 0.001) and higher TPOAb titer (odds ratio 11.8, p = 0.043) were risk factors for miscarriage. Higher TPOAb titer should be considered as one of the risk factors for miscarriage in infertile women, even if they have been treated with L-T4 for hypothyroidism.

Thyroid Disorders and In Vitro Outcomes of Assisted Reproductive Technology: An Unfortunate Combination?

Background: The impact of thyroid disorders on in vitro outcomes of assisted reproductive technology (ART) remains controversial. Therefore, the aim of our study was to investigate whether thyroid peroxidase antibodies (TPO-Abs)/thyroid autoimmunity (TAI) or thyroid function (serum thyrotropin [TSH])/subclinical hypothyroidism are associated with an altered number of oocyte retrieval (NOR), fertilization rate (FR), and embryo quality (EQ). Methods: Cross-sectional study in 279 women in a single center, comprising 297 cycles and 1168 embryos. In vitro data (NOR, FR, and EQ) were documented in two groups; one according to thyroid function in women without TAI (TSH ≤2.5 and >2.5 mIU/L) and one according to the presence/absence of TAI (determined by TPO-Abs). EQ was evaluated according to international criteria and classified as excellent/good and poor. Women treated with levothyroxine (LT4) were excluded. Furthermore, the impact of thyroid parameters on outcomes, normal NOR (>6 or 8) and high FR (>60%), was verified in a multivariable logistic regression model. Results: In women without TAI, 27% had TSH levels >2.5 mIU/L, the prevalence of TAI was 8%, and overall, 6% of women had TSH levels >4.2 mIU/L. NOR, FR, and EQ were comparable between study groups. In the regression analysis, women aged ≥30 years and receiving a high ovarian stimulation dosage (>2300 IU/cycle) had lower rates of normal NOR (odds ratio [OR] 0.18 [95% confidence interval, CI 0.04-0.72]; p = 0.016 and OR 0.17 [CI 0.06-0.48]; p < 0.001, respectively). Conclusions: Our results do not suggest an impact of thyroid antibodies/autoimmunity and (dys)function on ART in vitro outcomes.

The efficacy of acupuncture for the treatment and the fertility improvement in child-bearing period female with Hashimoto Disease: A randomized controlled study

BACKGROUND

Hashimoto thyroiditis (HT) is highly prevalent among reproductive-aged women and has a substantial negative impact on fertility. Currently, there is no specific treatment for Hashimoto thyroiditis. We hypothesize that acupuncture can halt or delay the progression of HT and improve fertility in child-bearing period female. We therefore designed a randomized controlled trial to test this hypothesis by comparing the therapeutic effect of acupuncture vs sham acupuncture in patients with Hashimoto thyroiditis.

METHODS

In this randomized controlled study, a total of 284 eligible patients will be assigned to acupuncture group (n = 142) or sham acupuncture group (n = 142) in a 1:1 ratio. All patients will receive 36 sessions in total for 12 consecutive weeks with the same acupoint prescription (RN23, ST9, RN17, RN4, RN6, ST36, SP6, KI6). The primary assessment is the titers of thyroid peroxidase antibodies (TPOAb) and thyroglobulin antibody (TGAb). Secondary outcomes include the thyroid function, ovarian function, the rate of primary ovarian insufficiency, and pregnancy outcome. The thyroid function and thyroid antibodies tests will be measured at weeks 0, 4, 8, and 12 after randomization. The ovarian function will be examined on the 2nd to 4th day of the menstrual period in the 1st month, 2nd month and 3rd month compared with baseline. Both the pregnancy outcome and the rate of primary ovarian insufficiency will be evaluated 1 year after treatment.

DISCUSSION

This will be the first large-scale trial specifically evaluating acupuncture therapy in child-bearing period female with Hashimoto thyroiditis. If the study confirms the effectiveness of acupuncture treatment, more consistent acupuncture therapy can be set up for clinical practice.

TRIAL REGISTRATION

Chinese Clinical Trials Register identifier, ChiCTR2000031320, registered on 27 March 2020.

Thyroid Hormones and Functional Ovarian Reserve: Systemic vs. Peripheral Dysfunctions

Thyroid hormones (THs) exert pleiotropic effects in different mammalian organs, including gonads. Genetic and non-genetic factors, such as ageing and environmental stressors (e.g., low-iodine intake, exposure to endocrine disruptors, etc.), can alter T4/T3 synthesis by the thyroid. In any case, peripheral T3, controlled by tissue-specific enzymes (deiodinases), receptors and transporters, ensures organ homeostasis. Conflicting reports suggest that both hypothyroidism and hyperthyroidism, assessed by mean of circulating T4, T3 and Thyroid-Stimulating Hormone (TSH), could affect the functionality of the ovarian reserve determining infertility. The relationship between ovarian T3 level and functional ovarian reserve (FOR) is poorly understood despite that the modifications of local T3 metabolism and signalling have been associated with dysfunctions of several organs. Here, we will summarize the current knowledge on the role of TH signalling and its crosstalk with other pathways in controlling the physiological and premature ovarian ageing and, finally, in preserving FOR. We will consider separately the reports describing the effects of circulating and local THs on the ovarian health to elucidate their role in ovarian dysfunctions.

Thyroid and Fertility: Recent Advances

Background: Thyroid disease is prevalent in women of reproductive age, while infertility is common in women with thyroid dysfunction. In this study, we review the recent advances in the field of thyroid and fertility since the publication of the 2017 American Thyroid Association pregnancy guidelines. Summary: Recent studies have confirmed associations of thyrotropin (TSH) elevation and/or thyroid autoimmunity with infertility and low ovarian reserve in subsets of women, and have led to a better understanding of the pathogenesis linking thyroid autoimmunity with infertility. Even though the benefit of treating patients with TSH >4 mIU/L has been confirmed in a large retrospective cohort study, two large randomized controlled trials have failed to show benefit of thyroid hormone on obstetrical outcomes in euthyroid women with thyroid autoimmunity. New data have emerged regarding the potential gonadal toxicity of radioactive iodine (RAI), based on its impact on ovarian reserve and sperm chromosomal abnormalities. Conclusions: There is continued evidence supporting an important role of thyroid hormone in regulation of reproductive tissues at many levels. Recent randomized trials have failed to identify a benefit of thyroid hormone in euthyroid women with thyroid autoimmunity. Further research in the field is needed to more completely delineate the relevant pathways and identify women who may benefit from levothyroxine treatment. The impact of RAI on fertility also merits further investigation.

Impact of Thyroid Autoimmunity on Ovarian Reserve, Pregnancy Outcomes, and Offspring Health in Euthyroid Women Following In Vitro Fertilization/Intracytoplasmic Sperm Injection

Background: Thyroid autoimmunity (TAI) is the most frequent autoimmune disease among reproductive-aged women. It has been related to premature ovarian insufficiency, but the mechanisms remain elusive, and its association with ovarian reserve in euthyroid women is debatable. Moreover, the impact of TAI on assisted reproduction is controversial: especially for women with diminished ovarian reserve (DOR), few studies are available. Therefore, the present study was aimed to look for an association between TAI and DOR, and to evaluate the effect of TAI on pregnancy outcomes and offspring health following assisted reproductive technology stratified by ovarian reserve. Methods: A total of 6213 euthyroid women from the Reproductive Hospital Affiliated to Shandong University between 2012 and 2017 were retrospectively included. The prevalence of DOR in women with negative or positive TAI was calculated, and pregnancy and neonatal outcomes after in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) cycles were compared between the TAI-positive and TAI-negative groups both in women with DOR and in those with normal ovarian reserve (NOR). Longitudinal growth parameters and temperament type of the offspring were also observed in the TAI-positive and TAI-negative groups. Results: The prevalence of DOR in women with positive TAI and those with negative TAI was not significantly different (4.09% vs. 2.96%, p = 0.053), even after stratifying patients by age. In women with DOR, the live birth rate, pregnancy loss rate, neonatal complication rate, and offspring outcomes between the TAI-positive and TAI-negative groups were comparable (p > 0.05). In women with NOR, a higher rate of live births (44.94% vs. 40.34%, p = 0.027) and a higher prevalence of congenital anomalies (4.68% vs. 2.14%, p = 0.005) were observed in the TAI-positive group. Conclusions: TAI had no impact on ovarian reserve in euthyroid women and had no association with IVF/ICSI outcomes in women with DOR. Although an increased incidence of congenital anomalies in the TAI-positive group was observed in women with NOR, an association between neonatal anomalies and TAI cannot be demonstrated. Large cohort studies to evaluate the effects of TAI on offspring health are warranted, and further experimental studies are required to explore the underlying mechanisms.

Subclinical Hypothyroidism Is Associated with Lower Ovarian Reserve in Women Aged 35 Years or Older

Background: Overt thyroid diseases have been identified as risk factors for female infertility. However, it remains largely unclear whether subclinical hypothyroidism (SCH), a very common thyroid disorder, is associated with female infertility. This study aimed to investigate the potential association between SCH and the ovarian reserve in women seeking infertility treatment. Methods: This retrospective study included 2568 women with normal thyroid function (n = 2279) or SCH (n = 289) who visited our clinic for infertility treatment. Ovarian reserve markers, including follicle-stimulating hormone (FSH) concentrations on days 2-4, the antral follicle count (AFC), and anti-Müllerian hormone (AMH) concentration, were compared between euthyroid women and those with SCH. Multiple linear and Poisson regression analyses were used to estimate the associations of SCH with ovarian reserve markers. These analyses were repeated separately in women aged <35 (n = 1349) and ≥35 years (n = 1219). Results: In the total study population, women with SCH had significantly lower AMH concentrations (median: 2.05 vs. 2.51 ng/mL, p = 0.015) and AFCs (median: 10.0 vs. 11.0, p = 0.013), compared with euthyroid women. In linear and Poisson regression analyses, SCH was significantly associated with a higher basal FSH concentration (mean difference = 1.13 mIU/mL [95% confidence interval (CI) 0.97 to 1.29 mIU/mL], p < 0.001), lower AMH concentration (mean difference = -0.27 ng/mL [CI -0.43 to -0.12 ng/mL], p = 0.001), and lower AFC (mean difference = -0.7 [CI -1.3 to -0.2], p = 0.005). In women aged ≥35 years, SCH was significantly associated with FSH (mean difference = 1.74 mIU/mL, p < 0.001) and AMH concentrations (mean difference = -0.40 mg/mL, p < 0.001) and AFC (mean difference = -0.8, p < 0.001). In women <35 years old, SCH was significantly associated with a higher FSH concentration (mean difference = 0.30 mIU/mL, p < 0.001), but not with AMH or AFC concentrations (p = 0.84 and 0.06, respectively). Thyroperoxidase antibody (TPOAb) positivity was not associated with measures of ovarian reserve. Conclusions: The data suggest that SCH is associated with decreased ovarian reserve during later reproductive age. TPOAb positivity was not associated with ovarian reserve. Future research is necessary to investigate the underlying molecular mechanisms regulating the diminished ovarian reserve in women with SCH and to evaluate whether levothyroxine supplementation may improve the ovarian function of women with SCH.

Overtime trend of thyroid hormones and thyroid autoimmunity and ovarian reserve: a longitudinal population study with a 12-year follow up

BACKGROUND

Ovarian reserve, vital for reproductive function, can be adversely affected by thyroid diseases. Despite alternations of thyroid hormones with ageing, data on interactions between the overtime trend of thyroid functions and ovarian reserve status has rarely been reported. We aimed to examine the overtime trend of thyroid hormones, thyroid peroxidase antibody (TPO Ab) and their associations with ovarian reserve status, identified by levels of age specific anti-mullerian hormone (AMH) in reproductive aged women, who participated in 12-year cohort of Tehran Thyroid Study (TTS).

METHODS

Reproductive age women(n = 775) without any thyroid disease or ovarian dysfunction were selected from the Tehran Thyroid Study cohort. Participants were divided into four age specific AMH quartiles (Q1-Q4), Q1, the lowest and Q4, the highest. AMH was measured at the initiation of study and thyroid stimulating hormone (TSH), free T4 (FT4), and TPO Ab were measured at baseline and at three follow up visits.

RESULTS

At baseline, there was no statistically significant difference in thyroid hormones between women of the four quartiles, although TPO Ab levels were higher in women of Q1. During the follow ups, FT4 was decreased in all quartiles (p < 0.05), whereas TPO Ab increased in Q1 (p = 0.02). Odds ratio of overall TPO Ab positivity in women of Q1 was 2.08 fold higher than those in Q4. (OR: 2.08, 95%CI: 1.16, 3.72; p = 0.01).

CONCLUSION

Women with the lowest ovarian reserves had higher levels of TPO Ab, with a positive trend of this antibody overtime in comparison to other quartiles, indicating that this group may be at a higher risk of hypothyroidism over time.

Association of Thyroid Function and Autoimmunity with Ovarian Reserve in Women Seeking Infertility Care

BACKGROUND

While overt thyroid disease is a well known risk factor for infertility, the potential consequences of mild thyroid dysfunction or thyroid autoimmunity remain unknown. Experimental studies suggest a considerable role for thyroid hormone in the physiological mechanisms of ovarian reserve, but translation of such findings to human studies remains rare. A potential role for thyroid function in female reproduction could be especially relevant when the cause of infertility remains unknown, such as in women with diminished ovarian reserve (DOR) or unexplained infertility. The aims of this study were to investigate the association of thyroid function and autoimmunity with markers of ovarian reserve day 3 follicle-stimulating hormone (FSH) concentrations and antral follicle count (AFC), and to investigate whether thyroid function or autoimmunity may have different effects in women with DOR or unexplained infertility.

METHODS

Thyrotropin, free thyroxine, thyroxine, free triiodothyronine (fT3), triiodothyronine, thyroid peroxidase antibodies (TPOAbs), and thyroglobulin antibodies (TgAbs), as well as AFC and the day 3 FSH concentration, were measured among women seeking fertility treatment at the Massachusetts General Hospital Fertility Center. Multiple linear or mixed regression models were used to study the association of thyroid function or autoimmunity with AFC or day 3 FSH.

RESULTS

In the total study population (436 women, 530 AFC measurements), there was no association of thyroid function or TPOAb positivity with AFC. However, TgAb positivity was associated with a higher AFC (mean difference = 3.4 [95% confidence interval (CI) 1.8-5.1], p < 0.001). In women with DOR or unexplained infertility, lower fT3 and TPOAb positivity were associated with a lower AFC (fT3: continuous nonlinear association, p = 0.009; TPOAb positivity: -2.3 follicles [confidence interval -3.8 to -0.5], p = 0.01), while TgAb positivity was not associated with AFC. Neither thyroid function nor thyroid antibody positivity was associated with the day 3 FSH concentration.

CONCLUSIONS

This study found that lower fT3 and TPOAb positivity are associated with a lower AFC in women with DOR or unexplained infertility. Future studies are required to replicate these findings and further elucidate the role of TgAbs and underlying mechanisms through which thyroid function and autoimmunity is associated with ovarian reserve.

An exploration on the influence of positive simple thyroid peroxidase antibody on female infertility

The aim of the present study was to explore the influence of positive simple thyroid peroxidase antibody (TPO-Ab) on female infertility. Venous blood was collected on an empty stomach from infertile female patients (all of whom were in line with the World Health Organization's diagnostic criteria for infertility) receiving treatments at The Affiliated Wuxi Maternity and Child Health Care Hospital of Nanjing Medical University from 2014 to 2017 to detect thyroid function and thyroid antibodies [thyroglobulin antibody (TG-Ab), TPO-Ab and thyroid microsome antibody (TM-Ab)]. A total of 529 patients with normal thyroid function, TG-Ab and TM-Ab were included in the present study; they were divided into the positive group (121 cases with positive TPO-Ab) and the negative group (408 cases with negative TPO-Ab). Comparisons of age, body mass index (BMI), basal hormone levels, irregular menstruation, tubal obstruction, premature ovarian failure (POF), endometriosis (EMT) and polycystic ovary syndrome (PCOS) between the two groups of patients were conducted in order to determine whether the differences were statistically significant. The incidence rate of EMT was 39.6% in the positive group and 17.1% in the negative group (P<0.05). The incidence rate of PCOS in the observation group was 43.9%, which was significantly higher than that of the control group (21.3%; P<0.01). The results revealed that the differences in age, BMI, basal hormone levels, irregular menstruation and POF between the two groups were not statistically significant (P>0.05). Finally, the factors that had statistical significance (EMT and PCOS) were stratified by different age groups to compare the incidence rate of positive results among the different age groups, thus concluding which age group was influenced to a greater extent by TPO-Ab. The results indicated that positive TPO-Ab may be associated with PCOS and EMT, though particularly with PCOS. Infertile PCOS patients aged 28–35 years old were influenced more by TPO-Ab than those in other age groups. Thus, it is recommended that thyroid autoantibodies are detected in infertile PCOS females aged 28–35 years old, and treatment should be administered as soon thereafter.