Autoimmune thyroid disease and ovarian hypofunction: a review of literature

Thyroid hormones(THs) are essential for the proper functioning of the ovaries, and multiple studies have shown that thyroid abnormalities, especially during adolescence and reproductive age, can lead to lifelong ovarian dysfunction. Autoimmune thyroid disease (AITD), one of the most common organ specific autoimmune diseases, is mainly mediated by cellular autoimmune reactions, and has strong inflammatory infiltration and immune active cells, including chemokines and cytokines, which are important components of ovarian aging. This suggests that autoimmune and inflammatory molecular processes may play a role in the emergence of ovarian dysfunction. The purpose of this review is to summarize recent in vivo and in vitro evidence of a complex relationship between AITD and ovarian dysfunction. AITD is closely related to the decline of ovarian function from the perspective of antibody, cytokine, oxidative stress, and genetic factors. Finally, some of the currently known treatments for AITD and hypo ovarian disease are summarized.

The association of thyroid autoimmunity with ovarian reserve in women with type 1 diabetes with and without polycystic ovary syndrome

The aim of the study was to investigate the relation between thyroid autoimmunity (TAI), reflected as the presence of thyroid peroxidase antibodies (TPOAb), and parameters of ovarian reserve in women with type 1 diabetes (T1DM) and polycystic ovary syndrome (PCOS). We studied 83 euthyroid women with T1DM (age - 26 ± 5 years, BMI - 24 ± 3 kg/m2) - 12 with PCOS and positive TPOAb (PCOS + TPOAb), 29 with PCOS with negative TPOAb (PCOS + noTPOAb), 18 without PCOS with positive TPOAb (noPCOS + TPOAb), 24 without PCOS with negative TPOAb (noPCOS + noTPOAb). Serum concentrations of anti-Müllerian hormone (AMH), sex hormones, TSH, thyroid hormones and TPOAb were assessed. The prevalence of TAI was comparable between PCOS and noPCOS. We did not observe differences in hormonal profile or AMH concentration between two PCOS groups-PCOS + TPOAb and PCOS + noTPOAb (p > 0.05). Women with PCOS + TPOAb had lower FSH concentration and higher LH/FSH index than noPCOS + noTPOAb (p = 0.027; p = 0.019, respectively). Moreover, PCOS + TPOAb had lower oestradiol level than noPCOS + TPOAb (p = 0.041). AMH concentration was higher in both groups with PCOS, independent of TPOAb presence, than in noPCOS + noTPOAb (both p < 0.001). The presence of positive TPOAb titre was not related to the studied parameters of ovarian reserve - AMH and ovarian follicle number. In multiple linear regression analysis, the only significant predictor of AMH in the whole studied group with T1DM was total daily insulin dose U/kg (β = - 0.264; p = 0.022). The presence of TAI did not affect the hormonal profile or ovarian reserve in women with T1DM with and without PCOS.

Hashimoto's Thyroiditis Negatively Influences Intracytoplasmic Sperm Injection Outcome in Euthyroid Women on T4 Substitution Therapy: A Retrospective Study

OBJECTIVE

The objective of this study was to analyze the impact of thyroid autoimmunity (TAI) on reproductive outcome parameters of intracytoplasmic sperm injection (ICSI) cycles as compared to TAI-negative ICSI cycles.

DESIGN

In this single in vitro fertilization (IVF) center retrospective study, 86 infertile women with elevated thyroid peroxidase or TGAb levels, but euthyroid after thyroxine replacement (study group), were compared to 69 female patients with no thyroid abnormalities (controls). Following ICSI treatment fertilization rate (FR), clinical pregnancy rate (CPR), miscarriage rate (MR), and live birth rate (LBR) were analyzed.

MATERIALS, SETTING, METHODS

All subjects with various infertility factors were treated with ICSI in university-based IVF center. Patients in the study group received thyroxine replacement and were euthyroid at IVF treatment. Before the IVF cycles, endocrinological parameters were uniformly assessed: thyroid function and antibodies, reproductive hormones (anti-Müllerian hormone [AMH], follicular stimulating hormone [FSH], luteinizing hormone, E2, PRL, testosterone, DHEAS, 17-OHP, AD) and OGTT (0-60-120 min glucose and insulin). Following descriptive comparison of laboratory parameters, age-adjusted analyses of FR, CPR, MR, and LBR were performed.

RESULTS

TAI-positive women were older (mean age 35.31 ± 4.95 vs. 32.15 ± 4.87 years; p = 0.002), had higher FSH (8.4 ± 3.4 vs. 7.4 ± 2.32 U/L; p = 0.024), higher E2 (53.94 ± 47.61 vs. 42.93 ± 18.92 pg/mL; p = 0.025) levels, while AMH (2.88 ± 2.62 vs. 3.61 ± 1.69 ng/mL; p = 0.0002) was lower. There were no differences in TSH levels (1.64 ± 0.96 vs. 1.66 ± 0.65 µIU/mL; p = 0.652) between the two groups. FT3 (2.63 ± 0.58 vs. 2.98 ± 0.55 pg/mL; p = 0.002) was lower and FT4 (1.3 ± 0.29 vs. 1.13 ± 0.21 ng/dL; p = 0.0002) was higher in the TAI-positive group, reflecting clinically irrelevant differences. Egg cell counts (6 ± 3.8 vs. 7.5 ± 3.95; p = 0.015) were lower in TAI and remained so following age adjustment. Although the overall ICSI FR did not differ (62.9% vs. 69.1%, p = 0.12), it was lower for patients under 35 with TAI showing decreasing differences in line with age. The CPR (36.04% vs. 69.56%; p < 0.001) and LBR (23.25% vs. 60.86%; p < 0.001) were lower, the MR (35.48% vs. 12.5%; p = 0.024) was higher in the TAI group, and these differences remained after age adjustment.

LIMITATIONS

Since the higher age of the study group may interfere with the effect of TAI, age adjustment calculations were necessary to perform to eliminate this confounding factor.

CONCLUSION

Despite optimal thyroid supplementation in clinical or subclinical hypothyroidism, the presence of TAI negatively influences CPR and is connected to a higher MR, thus resulting in a lower LBR after ICSI. Decreased FR with ICSI in TAI patients may also contribute to poorer outcomes, especially in younger women.

Elevated Thyroglobulin Antibody Level is Associated with Decreased Anti-Müllerian Hormone in Women of Reproductive Age

Purpose

Women with Hashimoto's thyroiditis (HT) have an increased risk of ovarian insufficiency. However, whether thyroid antibodies affect the ovarian reserve remains controversial. The aim of this study was to explore the possible relationship between anti-Müllerian hormone (AMH) and thyroid peroxidase antibody (TPOAb) and thyroglobulin antibody (TgAb) levels in women of reproductive age.

Methods

A total of 483 women between 18 and 45 years old who had their TPOAb, TgAb, thyroid-stimulating hormone (TSH), free thyroxine (FT4), and AMH levels measured on the same day were enrolled in this study. The levels of TSH, FT4, TPOAb, and TgAb, the prevalence of overt and subclinical hypothyroidism, and the positive rate of TPOAb and TgAb were compared between patients with low (below the 10th percentile), normal (10th to 90th percentile), and high (higher than the 90th percentile) AMH levels.

Results

The median AMH level was 1.72 (0.33-4.27) ng/mL. A total of 9.9% of patients had low AMH levels. The TgAb levels and the prevalence of TgAb positivity were higher in the low AMH group (37.62 (13.10-232.68) IU/mL, 35.42%) than in the normal (12.46 (10.0-67.04) IU/mL, 19.59%) and high (13.61 (10.0-95.74) IU/mL, 23.4%) AMH groups (p=0.001, p=0.040, respectively). Serum AMH levels were inversely correlated with TgAb levels (r = -0.114, p=0.013).

Conclusion

The AMH of women of reproductive age is affected by HT. Furthermore, women with the lowest AMH level had higher levels of TgAb and a positive rate of TgAb, and high TgAb levels may cause autoimmune damage to the ovaries.

TPOAb positivity can impact ovarian reserve, embryo quality, and IVF/ICSI outcomes in euthyroid infertile women

The aim of this study was to investigate the effects of positive anti-thyroid peroxidase (TPO) antibodies on fertility, embryo quality, and pregnancy outcomes in women with normal thyroid function. A cross-sectional study of 1223 infertile women who received assisted reproductive technology (ART) treatment for the first time was conducted at our hospital from January 2019 to March 2022. Overall, 263 infertile women were included, comprising 263 cycles and 1813 embryos, and were divided into a positive group and a control group based on TPO antibody levels. The positive group was further divided into two subgroups according to the median antibody titer, and the therapeutic indices and pregnancy outcomes for each group were compared. The results showed that the AMH level in the positive group was significantly lower than that in the control group (2.37 (1.26-3.63) ng/ml vs. 3.54 (1.74-5.41) ng/ml, p < 0.001). The high-quality embryo rate (40.04% vs. 45.49%, p = 0.034) and live birth rate (23.26% vs. 36.16, p = 0.035) of the positive group were lower than those of the control group; the miscarriage rate was higher than that of the control group (37.50% vs. 17.95%, p = 0.035). The live birth rate in the low-titer group was significantly higher than that in the high-titer group (32.56% vs. 13.95%, p = 0.041). Studies have shown that positive anti-thyroid peroxidase antibodies are associated with a decreased ovarian reserve and decreased embryo quality. High titers of anti-thyroid peroxidase antibodies can reduce the live birth rate.

Thyroid hormones and ovarian reserve: a comprehensive study of women seeking infertility care

BACKGROUND

Ovarian reserve is the number of oocytes remaining in the ovary and is one of the most important aspects of a woman's reproductive potential. Research on the association between thyroid dysfunction and ovarian reserve has yielded controversial results. In our study, we aimed to investigate the relationship between thyroid-stimulating hormone (TSH) levels and ovarian reserve markers.

METHODS

From 1443 women seeking infertility care, the data of 1396 women aged between 20-45 years old who had a body mass index between 18-30 kg/m2 were recruited for this retrospective study. The anti-Müllerian hormone (AMH) and TSH relationship was analyzed with generalized linear and polynomial regression.

RESULTS

Median age, follicle-stimulating hormone (FSH), AMH, and TSH levels were 36.79 years, 9.55 IU/L, 3.57 pmol/L, and 1.80 mIU/L, respectively. Differences between TSH groups were statistically significant in terms of AMH level, antral follicle count (AFC), and age (p = 0.007 and p = 0.038, respectively). A generalized linear regression model could not explain age-matched TSH levels concerning AMH levels (p > 0.05). TSH levels were utilized in polynomial regression models of AMH, and the 2nd degree was found to have the best fit. The inflection point of the model was 2.88 mIU/L.

CONCLUSIONS

Our study shows a correlation between TSH and AMH values in a population of infertile women. Our results are as follows: a TSH value of 2.88 mIU/L yields the highest AMH result. It was also found that AMH and AFC were positively correlated, while AMH and FSH were negatively correlated.

Polycystic ovary syndrome and thyroid disorder: a comprehensive narrative review of the literature

Background

Published data on the relationship between polycystic ovary syndrome (PCOS) and thyroid dysfunction are sparse and confusing.

Objective

To comprehensively review data available in the literature regarding the relationship between PCOS and the thyroid function, and its abnormalities.

Methods

Nine main areas of interest were identified and analyzed according to the available evidence: 1) Evaluation of thyroid function for PCOS diagnosis; 2) Epidemiology data on thyroid function/disorders in patients with PCOS, and vice versa; 3) Experimental data supporting the relationship between thyroid function/disorders and PCOS; 4) Effects of thyroid function/disorders on PCOS features, and vice versa; 5) Effect of thyroid alterations on the cardiometabolic risk in women with PCOS; 6) Effect of thyroid abnormalities on reproductive outcomes in women with PCOS; 7) Relationship between thyroid function/abnormalities in patients with PCOS who are undergoing fertility treatment; 8) Effect of treatments for thyroid diseases on PCOS; and 9) Effect of treatments for PCOS on thyroid function. An extensive literature search for specific keywords was performed for articles published from 1970 to March 2023 using PubMed and Web of Science. Data were reported in a narrative fashion.

Results

PCOS is a diagnosis of exclusion for which diagnosis is possible only after excluding disorders that mimic the PCOS phenotype, including thyroid dysfunctions. However, the tests and the cutoff values used for this are not specified. Many experimental and clinical data suggest a relationship between perturbations of the thyroid function and PCOS. Direct and unequivocal evidence on the effects of thyroid function/disorders on PCOS features are lacking. High thyroid-stimulating hormone levels and subclinical hypothyroidism may be associated with significant worsening of several intermediate endpoints of cardiometabolic risk in women with PCOS. Thyroid abnormalities may worsen reproductive outcomes, especially in patients undergoing fertility treatment. To date, there are no data demonstrating the efficacy of thyroid medications on fertility and cardiometabolic risk in women with PCOS. Lifestyle modification changes, metformin, and vitamin D seem to improve thyroid function in the general population.

Conclusion

PCOS and thyroid disorders are closely related, and their coexistence may identify patients with a higher reproductive and metabolic risk. Regular screening for thyroid function and thyroid-specific autoantibodies in women with PCOS, particularly before and during pregnancy, is highly recommended.

Mendelian randomization study of thyroid function and anti-Müllerian hormone levels

Objective

Although previous studies have reported an association between thyroid function and anti-Müllerian hormone (AMH) levels, which is considered a reliable marker of ovarian reserve, the causal relationship between them remains uncertain. This study aims to investigate whether thyrotropin (TSH), free thyroxine (fT4), hypo- and hyperthyroidism are causally linked to AMH levels.

Methods

We obtained summary statistics from three sources: the ThyroidOmics Consortium (N = 54,288), HUNT + MGI + ThyroidOmics meta-analysis (N = 119,715), and the most recent AMH genome-wide association meta-analysis (N = 7,049). Two-sample MR analyses were conducted using instrumental variables representing TSH and fT4 levels within the normal range. Additionally, we conducted secondary analyses to explore the effects of hypo- and hyperthyroidism. Subgroup analyses for TSH were also performed.

Results

MR analyses did not show any causality relationship between thyroid function and AMH levels, using normal range TSH, normal range fT4, subclinical hypothyroidism, subclinical hyperthyroidism and overt hypothyroidism as exposure, respectively. In addition, neither full range TSH nor TSH with individuals <50 years old was causally associated with AMH levels. MR sensitivity analyses guaranteed the robustness of all MR results, except for the association between fT4 and AMH in the no-DIO1+DIO2 group.

Conclusion

Our findings suggest that there was no causal association between genetically predicted thyroid function and AMH levels in the European population.

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.

Factors Associated with Poor Ovarian Reserve in Young Infertile Women: A Hospital-based Cohort Study

Background

In practice, we encounter many young infertile women with poor ovarian reserve though ovarian reserve starts to decline after 35 years of age. One of the established risk factors for poor ovarian reserve in young women is endometriosis. There are other conditions that are reported to be associated which require further research.

Aims

We aimed to study the prevalence of poor ovarian reserve and to find out the associated factors in women who are <35 years of age.

Settings and Design

This was a prospective observational cohort study conducted in a tertiary care setting.

Materials and Methods

Women aged more than 21 years and <35 years without Polycystic Ovarian Syndrome (PCOS) or ovarian dysgenesis with normal male factor were included after ethical approval. The sample size was 166 and serum anti-Mullerian hormone (AMH) was estimated by immunoenzymatic assay and expressed in ng/ml. AMH ≤0.99 ng/ml was considered poor ovarian reserve. Apart from established risk factors, the proposed risk factors studied were age 31-35 years, presence of medical disorders, gynaecological pathology and history of repeated ovulation induction (OI).

Statistical Analysis Used

Data were analysed by SPSS version 25. Chi-square test and Fisher's exact test were used to compare the variables between normal ovarian reserve and poor ovarian reserve. Risk estimation was done by logistic regression and was expressed in odds ratio (OR).

Results

Poor ovarian reserve was diagnosed in 40% of this cohort, and 62% were between 31 and 35 years. After adjusting for age >30 years, women with endometrioma, hypothyroidism and prior history of ≥3 cycles of OI were found to be having poor ovarian reserve (OR was 5.7, 2.5 and 2.3, respectively).

Conclusion

Poor ovarian reserve was present in 40% of young women, and significantly associated factors were hypothyroidism and history of repeated multiple OI. This could be a confounder for other underlying mechanisms driving early exhaustion of ovarian reserve in certain young women. Hence, along with established risk factors, these women should undergo AMH testing irrespective of age.

Preconceptional thyroid stimulating hormone level and fecundity: a community-based cohort study of time to pregnancy

OBJECTIVE

To investigate the association between preconception thyroid stimulating hormone (TSH) level and time to pregnancy within a community-based population.

DESIGN

A community-based cohort study.

SETTING

Two free preconception check-up centers.

PATIENT(S)

Women who enrolled in the National Free Preconception Check-up Projects from January 1, 2018 to December 31, 2018 in Tianhe and Zengcheng districts of Guangzhou city.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Time to pregnancy.

RESULT(S)

A total of 1,478 women were eligible for the analysis; of these, 1,401 had a preconception TSH level within the range of 0.50 and 5.59 mIU/L (2.5th-97.5th percentiles) were taken as target study population. Among them, 968 (69.1%) couples achieved pregnancy within the first 6 months and 1,082 (77.2%) within 12 months. Dichotomized by the recommended cut-off value of 2.5 mIU/L, the percentage of women conceived in the high TSH level category (2.50-5.59 mIU/L) was comparable to that of the low category (0.50-2.49 mIU/L) (79.0% vs. 78.1%), with a crude fecundity odd ratio of 0.99 (95% confidence interval at 0.87-1.13). No statistically significant difference was observed after the adjustment in all models. Continuous TSH level was further examined, and the nonlinear association between TSH level and fecundity odds ratios was of no statistical significance.

CONCLUSION(S)

Preconception TSH level was not associated with fecundity in a healthy community-based population. Women attempting pregnancy with a TSH level ≥ 2.5 mIU/L can be reassured that they are unlikely to have an increased time to pregnancy.

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.

Evaluation of anti-Müllerian hormone in pre-menopausal women stratified according to thyroid function, autoimmunity and age

Background

AMH is a reliable index of ovarian reserve. It is not clear whether, or how much, thyroid function and/or thyroid autoimmunity can impair ovarian function and AMH secretion in the long term.

Aim

This retrospective cross-sectional study compared AMH levels in pre-menopausal women with/without positive thyroid autoimmunity or hypofunction.

Methods

From January 2019 to May 2022, AMH was evaluated in 250 pre-menopausal women not undergoing assisted fertility procedures who were referred to a secondary endocrine centre. Thyroid function and autoimmunity, sonographically measured thyroid volume, FSH and E2 in the early follicular phase, and PRL and progesterone in the luteal phase were also evaluated. Exclusion criteria were: age < 18 years, genetic hypogonadism, pregnancy and previous treatments that have potentially damaging effects on gonads.

Results

We evaluated 171 women (mean age ± SD: 31.5 ± 9.0 years) off L-T4 treatment and 79 women on L-T4 treatment (39.7 ± 9.5 years; P < 0.001). AMH (median, IQR, CI) was 16.1 pmol/l (7.1 – 35.7 pmol/l, 21.4 – 29.9 pmol/l) and 7.6 pmol/l (1.4 – 17.8 pmol/l, 8.6 – 14.7 pmol/l; P < 0.001), respectively. When the women were stratified according to age (18-25, 26-30, 31-35, 36-40, 41-45, > 46 years) no significant difference emerged between those on/off L-T4 treatment in groups of the same age-range. In women on- or off-L-T4 treatment, AMH was negatively related with age on univariate and multivariate analyses (P < 0.0001). In both groups, AMH was negatively related to FSH (P < 0.0001). On multivariate analysis, AMH was positively related to the age of the mother on spontaneous menopause (P = 0.006) and negatively to thyroid volume (P = 0.02) in women on L-T4. AMH levels were significantly (P = 0.03) higher in TPOAb-negative than in TPOAb-positive women, but age was significantly (P = 0.001) lower in TPOAb-negative than in TPOAb-positive women.

Conclusions

In our cohort of women, age proved to be a better predictor of AMH levels than any of the other factors linked to thyroid function and autoimmunity. Our data do not support the hypothesis that subclinical hypothyroidism and/or autoimmunity are associated with decreased ovarian reserve. However, a larger number of cases is needed in order to obtain conclusive data.

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 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.

Body Composition and Serum Anti-Müllerian Hormone Levels in Euthyroid Caucasian Women With Hashimoto Thyroiditis

Objective

Women with Hashimoto thyroiditis (HT) are characterized by increased incidence of infertility and disturbances in body composition. Serum anti-Müllerian hormone (AMH), which reflects functional ovarian reserve, is decreased in women with HT and it be related to body mass. The aim of the present study was to investigate the relation between serum levels of AMH and body composition in HT compared to control group.

Patients and Methods

We examined 85 euthyroid women: 39 subjects with HT and 46 control women. Body composition was analysed by dual-energy X-ray absorptiometry and with bioimpedance method. Serum concentrations of AMH, leptin, TSH, thyroid hormones were assessed.

Results

We observed lower serum concentration of AMH in women with HT in comparison to the control group (p=0.01), but without differences in serum concentration of leptin between studied groups (p=0.28). Women with HT were characterized by higher %body fat (p=0.01) estimated with bioimpedance method without differences in BMI, android and gynoid fat mass and visceral adipose tissue (VAT) mass estimated with DXA method when compared to the control group (all p>0.05). We found a negative relationship between serum concentration of AMH and %body fat (r=-0.38,p=0.03) in women with HT. Additionally, in HT group, the relationship between serum levels of AMH and leptin was not statistically significant (r=0.01,p=0.96). We observed a relationship between serum concentration of leptin and BMI, %body fat mass, android, gynoid and VAT mass in HT and in the control group (all p<0.01).

Conclusions

Women with HT are characterized by lower levels of AMH and it is associated with higher fat mass, independently of serum levels of leptin.

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.

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.

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.

Correlation Analysis Between Ovarian Reserve and Thyroid Hormone Levels in Infertile Women of Reproductive Age

OBJECTIVE

To analyze the correlation between ovarian reserve and thyroid function in women with infertility.

METHODS

Retrospective analysis of the data of 496 infertility patients who visited the clinic between January 2019 and December 2020. According to the TSH level, it is grouped into <2.5 mIU/L, 2.5~4.0mIU/L and ≥4.0 mIU/L or according to the positive/negative thyroid autoimmune antibody. The relationship was assessed through the ovarian reserve, thyroid function, and anti-Müllerian hormone (AMH) levels in infertile patients. On the other hand, the patients are divided into groups according to age (≤29 years old, 30-34 years old and ≥35 years old), basic FSH (<10 IU/L and ≥10 IU/L), and AMH levels. The ovarian reserve was evaluated through the AMH and the antral follicle count (AFC).

RESULTS

The average age of the patients was 30.31 ± 4.50 years old, and the average AMH level was 5.13 ± 4.30 ng/mL. 3.63% (18/496) of patients had abnormal TSH levels (normal: 0.35-5.5 mIU/L), the positive rate of thyroid peroxidase antibody (TPOAb) was 14.52% (72/496), the positive rate of anti-thyroglobulin antibody (TgAb) was 16.94% (84/496), and the positive rate of TPOAb and TgAb was 10.48% (52/496). After grouping according to TSH level or thyroid autoimmune antibody positive/negative grouping, the analysis found that there was no statistical significance in age, AMH level and basic FSH level among the groups (P>0.05). There were no significant differences in the levels of TSH, FT3, and FT4 among different ages, AMH, and FSH levels (P>0.05).

CONCLUSION

There is no significant correlation between ovarian reserve and thyroid function in infertile women.

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.

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.

Ovarian Reserve and Serum Concentration of Thyroid Peroxidase Antibodies in Euthyroid Women With Different Polycystic Ovary Syndrome Phenotypes

Objective: It has been shown that women with polycystic ovary syndrome (PCOS), as well as Hashimoto's thyroiditis (HT), are characterized by increased incidence of infertility. Serum anti-Müllerian hormone (AMH), which reflects ovarian reserve, is elevated in PCOS women and is decreased in women with HT. The Rotterdam criteria recognize four clinical PCOS phenotypes, i.e., phenotypes A, B, C, and D. The aim of the present study was to investigate the relation between serum concentrations of thyroid peroxidase antibodies (TPOAbs) and ovarian reserve in different PCOS phenotypes. Patients and methods: We examined 141 women with PCOS [phenotype A was diagnosed in 67 (47.5%) women, phenotype B in 30 (21.3%), phenotype C in 28 (19.9%), and phenotype D in 16 (11.3%)] and 88 control subjects of similar age; all women were euthyroid. Serum concentrations of AMH, thyroid-stimulating hormone (TSH), thyroid hormones, and TPOAbs were assessed. Results: We observed positive serum TPOAbs in 21.9% women with PCOS and in 23.9% controls (p = 0.07). We did not find differences in the frequency of detection of positive serum TPOAbs between phenotypes A, B, and C and the control group (p > 0.05). We did not observe a difference in AMH levels between TPOAbs-positive and TPOAbs-negative women, both in the control group and the PCOS women (all p > 0.05). However, serum AMH concentration was markedly higher in the whole PCOS group (p < 0.01) and in phenotype A (p < 0.01) vs. controls when the serum concentration of TPOAbs was negative. In the groups with positive serum levels of TPOAbs, serum concentration of AMH did not differ between PCOS phenotypes and controls (p = 0.23). Additionally, we observed that serum AMH concentration was related to the level of TPOAbs in the PCOS group (r = -0.4, p = 0.02). Conclusions: The frequency of serum detection of positive TPOAbs did not differ between PCOS phenotypes with clinical/biochemical hyperandrogenism and the control group. The observation of the difference in serum AMH between the PCOS and control groups only in TPOAbs negative women together with the inverse relation of TPOAbs with serum AMH only in the PCOS group might suggest that ovarian reserve is influenced by TPOAbs in PCOS.

[Relationship of the ovarian reserve with autoimmune thyroid diseases in the reproductive period]

AIM

To compare ovarian reserve in healthy women of reproductive age - carriers of antithyroid antibodies (ATA) and in healthy women of reproductive age negative for ATA.

MATERIALS AND METHODS

70 healthy women of young reproductive age in the state of euthyroidism (from 18 to 38 years old) were examined. Participants were divided into equal groups (n=35) depending on the status of the presence of antithyroid antibodies (AT-TPO, AT-TG). On the 2nd-4th days of the menstrual cycle, the following markers of the ovarian reserve were determined: serum levels of anti-Müllerian hormone (AMG), inhibin B, FSH, LH, estradiol, testosterone and progesterone, as well as ultrasound parameters - the number of antral follicles and the volume of the ovaries. In addition, to determine the predisposition to premature ovarian failure, an analysis was performed to the number of CGG repeats in the FMR1 gene.

RESULTS AND DISCUSSION

Statistically significantly differs such parameters as the level of estradiol and testosterone, while the differences were not clinically significant. All the parameters evaluated were within the normal range, the main predictors of the ovarian reserve (levels of AMG and inhibin B, the number of antral follicles) remained in the normal range. An increase in the number of repeats of CGG in the FMR1 gene was not detected in any of the participants in the study.

CONCLUSION

In healthy young reproductive age women, the status of ATA does not have a direct effect on the ovarian reserve.

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.

Evaluation of the Ovarian Reserve in Adolescents with Hashimoto’s Thyroiditis Using Serum Anti-Müllerian Hormone Levels

OBJECTIVE

This study aims to evaluate ovarian reserve in adolescent girls with Hashimoto’s thyroiditis (HT) by assessment of serum anti-Müllerian hormone (AMH) levels. It was hypothesized that HT decreases ovarian reserve and AMH levels are lower in the HT group.

METHODS

Thirty HT patients, aged between 10-18 years, and 30 healthy girls as the control group were enrolled in this cross-sectional study. The mean serum AMH levels of the groups were compared using the Mann-Whitney U test.

RESULTS

There was no statistically significant difference between the patient and the control groups in terms of serum AMH levels. There was a negative correlation between serum AMH and thyroid stimulating hormone (TSH) levels and no correlation between serum AMH and anti-thyroid peroxidase (anti-TPO) or anti-thyroglobulin (anti-Tg) antibody levels.

CONCLUSION

Our results show that ovarian reserve of adolescent girls, as measured by serum AMH levels, is not affected by HT. Autoimmune damage to the ovaries may take time and the adolescent period may be too early to see these effects. Follow up of the patients for reproductive abnormalities and initiation of prospective studies is recommended.

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.

Risk factors for inadequate response to ovarian stimulation in assisted reproduction cycles: systematic review

PURPOSE

Controlled ovarian stimulation is a fundamental part of a successful assisted reproduction treatment, and recognizing patients at risk of a poor response allows the development of targeted research to propose new treatment strategies for this specific group. The objective of this systematic review was to determine risk factors for poor ovarian response (POR) to controlled stimulation in assisted reproduction cycles described in the literature.

METHODS

The primary databases MEDLINE, Cochrane, LILACS, and SciELO were consulted, using specific terms with a restriction for articles in English or Portuguese published in the last 10 years.

RESULTS AND CONCLUSION

Our data suggest that environmental endocrine disruptors, tobacco, genetic mutations, endometriomas, ovarian surgery, chemotherapy, and short menstrual cycles are factors that influence stimulation in assisted reproduction cycles. Further studies are necessary for characterizing patients with prior risk factors.

Anti-Müllerian hormone in pre-menopausal females after ablative radioiodine treatment for differentiated thyroid cancer

PURPOSE

In recent years, anti-Mullerian hormone (AMH) has been considered a reliable index of ovarian reserve. There are few data on AMH values in thyroid cancer. The aim of this study was to evaluate AMH levels in pre-menopausal women with a history of low-risk thyroid cancer.

METHODS

Thirty-four women (aged 40.7 ± 6.7 years) were studied 7.1 ± 0.9 years after surgery and at least one RAI treatment. A group of 23 thyroid cancer women (41.6 ± 7.4 years) who had undergone only thyroidectomy served as controls. AMH, follicle-stimulating hormone (FSH) and estradiol were assayed on days 2-3, and prolactin and progesterone levels on days 21-24 of the menstrual cycle.

RESULTS

Pregnancy (RAI group 62%; control group 61%) and miscarriage rates (18% and 26%) were similar. AMH levels were similar in the RAI (10.7 ± 1.7 pmol/l) and control (17.5 ± 4.7 pmol/l) groups. Regular menses were reported in 41% and 52% of RAI and control subjects, respectively. Non-ovulatory cycles were noted in 26% and 35% of RAI and control women, respectively. AMH levels were found to be negatively correlated with age (RAI group P = 0.0003; control group P = 0.0001) and FSH, and positively correlated with progesterone, but not with the other hormonal parameters.

CONCLUSIONS

AMH should replace FSH in the evaluation of gonadal reserve in pre-menopausal thyroid cancer women. At present, age is the only predictor of AMH levels. About one out of two women with a history of thyroid cancer suffers from menstrual dysregulation, but infertility must be considered a low risk.

Evaluation of ovarian reserve in women with overt or subclinical hypothyroidism

INTRODUCTION

Thyroid dysfunction is among the most common autoimmune disorders in women of reproductive age. Previous studies have shown the association between autoimmune thyroid disease (AITD) and infertility. Anti-Müllerian hormone (AMH) is secreted by granulosa cells and is a useful marker for assessment of ovarian reserve. In the present study, we sought to evaluate the ovarian reserves of women with autoimmune thyroid disorder by measurement of AMH values.

MATERIAL AND METHODS

This prospective study included women with newly diagnosed AITD aged between 20 and 40 years. Patients were divided into three groups: subclinical hypothyroidism (SCH, n = 21), overt hypothyroidism (OH, n = 21) and controls (CG, n = 32). Study parameters included serum free T4, free T3, thyroid-stimulating hormone, anti-thyroglobulin, anti-thyroid peroxidase antibodies, follicle-stimulating hormone, luteinizing hormone, estradiol and AMH concentrations measured in the early follicular phase. Antral follicle count (AFC) was assessed with ultrasound. Body mass index (BMI) and waist circumference of the patients were noted.

RESULTS

No significant difference was found among SCH, OH and CG in regard to ovarian reserves measured by AMH values (p = 0.19) and AFC (p = 0.80). A significant negative correlation was found between AMH and BMI (r = -0.382, p = 0.001). Anti-Müllerian hormone and waist circumference (r = -0.330, p = 0.004) were also negatively correlated.

CONCLUSIONS

Although AMH values were not significantly different among groups, AMH values were lower in OH and SCH patients, indicating a possible need for close monitoring of these patients.

Levothyroxine supplementation improves serum anti-Müllerian hormone levels in infertile patients with Hashimoto's thyroiditis

AIM

Thyroid dysfunction and autoimmunity are associated with an adverse effect on fertility. An aberrant high thyroid stimulating hormone level is associated with diminished ovarian reserve in women of reproductive age; however, the utility of levothyroxine (LT4) replacement for infertile patients with subclinical hypothyroidism is still under discussion. The aim of this study was to investigate whether LT4 supplementation for infertile patients with subclinical hypothyroidism improves impaired ovarian function.

METHODS

We measured levels of serum thyroid-related hormones and a biomarker of ovarian function, anti-Müllerian hormone (AMH) in infertile women from 2014 to 2015. Out of a consecutive 1431 infertile patients, 311 patients with an elevated thyroid stimulating hormone level (≥ 2.5 μIU/mL) underwent detailed thyroid examinations, including blood tests of thyroid antibodies. We recruited 174 infertile patients, excluding patients with factors impacting ovarian and thyroid function. We evaluated alterations in AMH and thyroid related hormone levels during LT4 supplementation and infertility treatment with assisted reproductive technology.

RESULTS

After LT4 supplementation, no significant change in the average AMH level was detected overall. However, the AMH level in 35 patients with Hashimoto's disease increased significantly after treatment (1 month 1.3 ± 0.5 fold, P = 0.007; 3 months 1.3 ± 0.4 fold, P = 0.040). The AMH level in patients with thyroglobulin antibody-positive and thyroid peroxidase antibody-negative also significantly increased after LT4 treatment (1 and 3 months 1.5 fold; P = 0.023).

CONCLUSION

In the patients with Hashimoto's disease, preconception LT4 treatment may relieve adverse effects, including autoimmune antibodies, and support follicular development.

The utility of anti-Müllerian hormone in women with chronic kidney disease, on haemodialysis and after kidney transplantation

Women with renal disease have menstrual and gonadal dysfunction manifesting as hormonal imbalance. Anti-Müllerian hormone (AMH) is a potential measure of ovarian reserve. We examined circulating AMH concentrations in young women with renal failure, determined associations with clinical characteristics, and compared AMH with age-matched healthy individuals. AMH was measured in 77 women: 26 had chronic kidney disease (CKD), 26 were on haemodialysis (HD), and 25 had a kidney transplant. Random AMH levels were highest in women on HD [HD 2.9 (1.1-5.2), CKD 1.6 (0.7-2.2), transplant 1.5 (1.0-4.2) ng/ml]. On multiple linear regression, AMH was 53% higher [95% CI 0.20-0.98, P = 0.002] in women on HD and decreased by 20% per 5-year increase in age (P < 0.001). AMH was 43% lower in women with renal failure compared with 600 age-matched controls [1.7 (0.9-3.8) versus 3.0 (1.9-5.0) ng/ml, P < 0.001]; however, we found no difference in AMH between those on HD and healthy individuals [2.9 (1.1-5.2) versus 3.0 (1.9-5.0) ng/ml]. AMH may be a useful biomarker in female renal patients with non-dialysis dependent renal disease pursuing pregnancy. In contrast, AMH levels are higher in HD but unlikely to reflect ovarian reserve.

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

BACKGROUND

While screening of thyroid peroxidase antibody (TPOAb) has been recommended in women with primary ovarian insufficiency, the relationship between thyroid autoimmunity (TAI) and ovarian reserve remains undetermined. Because the TAI prevalence was reported to be different between different ethnic/racial groups, this study aimed to investigate the TAI prevalence in Chinese women with variable ovarian reserve.

METHODS

This is a cross-sectional study conducted in a university infertility clinic between October 2013 and March 2016. Among patients at their first entry to the infertility clinic, a total of 1044 patients with available results of anti-Müllerian hormone (AMH), thyrotropin (TSH), TPOAb, and thyroglobulin antibody (TgAb) were enrolled. The TSH levels and the prevalence of positive TPOAb and positive TgAb were compared between patients with low, normal, and high ovarian reserve categorized with age-specific AMH levels.

RESULTS

For the whole study population, the TSH levels, TPOAb positivity, and TgAb positivity were comparable between patients with variable ovarian reserve. However, after patients with known causes compromising ovarian reserve (iatrogenic or genetic) were excluded, only TPOAb positivity became significantly different between patients with low (22.7%), normal (14.0%), and high ovarian reserve (10.3%; p = 0.012). The TPOAb levels were not significantly correlated to AMH levels (Spearman's ρ = -0.027; p = 0.413). For the infertile subgroup, TPOAb positivity was significantly associated with idiopathic low ovarian reserve in unexplained infertility (low ovarian reserve: 28.6%; normal: 15.7%; high: 9.5%; p = 0.020).

CONCLUSIONS

Idiopathic low ovarian reserve was associated with more frequent positive TPOAb rather than thyroid function or TgAb positivity in Chinese women.

A post-publication analysis of the idealized upper reference value of 2.5 mIU/L for TSH: Time to support the thyroid axis with magnesium and iron especially in the setting of reproduction medicine

Laboratory medicine approaches the evaluation of thyroid function mostly through the single determination of the blood level of thyroid stimulating hormone (TSH). Some authors have suggested an upper reference value for TSH of 2.5 mIU/L. This suggestion has not been confirmed by recent clinical studies. These studies have delivered a clinically valid reference range going from 0.3 to 3.5 mIU/L. These values are valid for both for the general population as well as in the setting of fertility and pregnancy. Current biochemical evidence about the elements required to maintain thyroid function shows that these not only include dietary iodine but also magnesium, iron, selenium and coenzyme Q10. Iron is important for the synthesis of thyroid peroxidase; magnesium-ATP contributes to the active process of iodine uptake; iodine has to be sufficiently present in the diet; selenium acts through selenoproteins to protect the thyroid cell during hormone synthesis and in deiodination of thyroxine; coenzyme Q10 influences thyroid vascularity. As a consequence, good clinical practice requires additional biochemical information on the blood levels of magnesium, selenium, coenzyme Q10 as well as iron status. Since these elements are also important for the maintenance of reproductive function, we postulate that they constitute the connecting link between both endocrine systems.

Prolonged hypothyroidism severely reduces ovarian follicular reserve in adult rats

Background

There is substantial evidence both in humans and in animals that a prolonged reduction in plasma thyroid hormone concentration leads to reproductive problems, including disturbed folliculogenesis, impaired ovulation and fertilization rates, miscarriage and pregnancy complications. The objective of the present study is to examine the consequences of chronic hypothyroidism, induced in adulthood, for the size of the ovarian follicle pool. In order to investigate this, adult female rats were provided either a control or an iodide deficient diet in combination with perchlorate supplementation to inhibit iodide uptake by the thyroid. Sixteen weeks later animals were sacrificed. Blood was collected for hormone analyses and ovaries were evaluated histologically.

Results

At the time of sacrifice, plasma thyroid-stimulating hormone concentrations were 20- to 40-fold increased, thyroxine concentrations were negligible while tri-iothyronin concentrations were decreased by 40% in the hypothyroid group, confirming that the animals were hypothyroid. Primordial, primary and preantral follicle numbers were significantly lower in the hypothyroid ovaries compared to the euthyroid controls, while a downward trend in antral follicle and corpora lutea numbers was observed. Surprisingly the percentage of atretic follicles was not significantly different between the two groups, suggesting that the reduced preantral and antral follicle numbers were presumably not the consequence of increased degeneration of these follicle types in the hypothyroid group. Plasma anti-Müllerian hormone (AMH) levels showed a significant correlation with the growing follicle population represented by the total ovarian number of primary, preantral and antral follicles, suggesting that also under hypothyroid conditions AMH can serve as a surrogate marker to assess the growing ovarian follicle population.

Conclusions

The induction of a chronic hypothyroid condition in adult female rats negatively affects the ovarian follicular reserve and the size of the growing follicle population, which may impact fertility.

Antimüllerian hormone among women with and without type 1 diabetes: the Epidemiology of Diabetes Interventions and Complications Study and the Michigan Bone Health and Metabolism Study

OBJECTIVE

To compare concentrations of antimüllerian hormone (AMH) in women with and without type 1 diabetes.

DESIGN

Cross-sectional analysis of longitudinal studies, adjusting for repeated measures.

SETTING

Not applicable.

PATIENT(S)

Women aged 30-45 years who had not undergone oophorectomy, hysterectomy, or natural menopause at the time of AMH measurement were included (n = 376 in the Michigan Bone Health and Metabolism Study and n = 321 in the Epidemiology of Interventions and Complications Study). Linear mixed regression was used to evaluate whether AMH concentrations differed by diabetes status, adjusting for repeated measurements of AMH within individual women, body mass index, smoking status, and oral contraceptive use.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Concentrations of AMH.

RESULT(S)

In unadjusted comparisons, women with and without diabetes had similar median AMH values before 35 years of age, although women with type 1 diabetes had a lower proportion of women with elevated AMH concentrations (≥5.0 ng/dL). After adjustment for covariates and multiple observations per woman, log AMH concentrations were significantly lower among women with type 1 diabetes compared with women without diabetes (β-coefficient -1.27, 95% confidence interval [-2.18, -0.36] in fully adjusted models) before 35 years of age.

CONCLUSION(S)

Before 35 years of age, women with type 1 diabetes have lower AMH levels than women without diabetes. Further investigation is needed to determine the etiologies of this difference and how it may contribute to reproductive disorders among women with type 1 diabetes.

The impact of thyroid autoimmunity on IVF/ICSI outcome: a systematic review and meta-analysis

BACKGROUND

Thyroid autoimmunity (TAI) is the most frequent autoimmune condition and the first cause of thyroid dysfunction among women of reproductive age. Notably, it has been associated with adverse obstetric outcomes during all trimesters of pregnancy. Furthermore, since most studies show an increased prevalence of TAI among women attending infertility clinics, a detrimental impact of this condition on natural fertility and on the rate of success of assisted reproductive techniques has been suggested. However, to date, the results have been inconsistent.

OBJECTIVE AND RATIONALE

The objective of this study was to define the relation between TAI per se and the outcome of in vitro fertilisation (IVF)/intracytoplasmic sperm injection (ICSI) cycles.

SEARCH METHODS

A systematic literature review and meta-analysis were conducted. A Medline search was performed to identify all the comparative studies published from January 1990 to November 2015 in the English language literature on IVF/ICSI outcome in women with and without TAI, using combinations of the medical subject heading terms 'thyroid autoimmunity', 'thyroid autoantibodies', 'IVF', 'ICSI', 'pregnancy', 'miscarriage' and 'delivery'. The primary outcome was live birth rate (LBR). Our secondary outcomes were number of oocytes retrieved (NOR), fertilisation rate (FR), implantation rate (IR), clinical pregnancy rate (CPR) and miscarriage rate (MR). We also extracted data on mean age and basal serum concentrations of thyroid stimulating hormone (TSH) and performed a meta-regression analysis to assess the effect of these two covariates on CPR and MR.

OUTCOMES

We selected 12 studies for the meta-analysis. Six of the included studies were prospective cohort studies, and six were retrospective cohort studies. Compared with women with negative TAI, women with positive TAI had a lower LBR (odds ratio (OR) 0.73; 95% confidence interval (CI) [0.54-0.99]; P = 0.04; 9 studies; 4396 women; I2 = 41%), a higher MR (OR 1.44; 95% CI [1.06-1.95]; P = 0.02; 12 studies; 4876 women; I² = 35%), a similar CPR (OR 0.90; 95% CI [0.77-1.06]; P = 0.22; 12 studies; 4876 women; I² = 7%), a similar number of oocytes (standardized mean difference [SMD] 0.10; 95% CI [-0.09 to 0.29]; P = 0.28; 5 studies; 1506 women; I² = 47%), a similar FR (OR 1.11; 95% CI [0.97-1.27]; P = 0.13; 3 studies; 1082 women; I² = 0%) and a similar IR (OR 0.98; 95% CI [0.73-1.32]; P = 0.91; 2 studies; 918 women; I² = 0%). Both mean age (SMD 0.96; 95% CI [0.66-1.27]; P < 0.00001; 9 studies; 3256 women; I² = 85%) and serum TSH (SMD 0.24; 95% CI [0.15-0.34]; P < 0.00001; 6 studies; 2098 women; I² = 59%) were higher in women with TAI. However, neither of these two covariates were significantly associated with CPR or MR.

WIDER IMPLICATIONS

TAI does not impact on IVF/ICSI outcome in terms of NOR and likelihood of fertilisation, implantation and clinical pregnancy. On the contrary, the presence of thyroid autoantibodies may have a detrimental effect on the course of a pregnancy, determining an increased risk of miscarriage and a decreased chance of live birth. However, given the possible modifying effects of age and serum TSH, further evidence is warranted prior to drawing inferences on causality.

What affects functional ovarian reserve, thyroid function or thyroid autoimmunity?

BACKGROUND

Thyroid dysfunction is the most common autoimmune endocrine disorder in women of reproductive age, and is associated with menstrual irregularities, anovulation and infertility. Whether it is thyroid function or thyroid autoimmunity that affects functional ovarian reserve (FOR, i.e., the small growing ovarian follicle pool) reflected in anti-Müllerian hormone (AMH) has, however, remained under dispute.

METHODS

We investigated in 225 infertile women whether thyroid function, after adjustment for thyroid autoimmunity, affects FOR within what is considered normal thyroid function (TSH, 0.4-4.5μIU/mL) by assessing AMH levels in reference to TSH levels, stratified for TSH < or ≥3.0μIU/mL. Thyroid autoimmunity was defined by presence of anti-thyroid peroxidase, -thyroglobulin and/or -thyroid receptor antibodies.

RESULTS

Mean age of studied women was 38.4 ± 5.0 years; their mean AMH was 1.3 ± 2.0 ng/mL and mean TSH 1.8 ± 0.9 μIU/mL. Thyroid autoimmunity was present in 11.1 % of patients. Women with TSH <3.0μIU/mL presented with significantly higher AMH compared to those with TSH ≥3.0μIU/Ml (P = 0.03). This difference remained significant after adjustment for thyroid autoimmunity as well as age (P = 0.02).

CONCLUSIONS

Even after adjustment for thyroid autoimmunity and age, TSH <3.0μIU/mL in euthyroid infertility patients is associated with significantly better FOR (higher AMH) than TSH ≥3.0μIU/mL. This observation suggests a direct beneficial effect of lower TSH levels on follicular recruitment, and warrants investigations of thyroxin supplementation in infertile women with TSH levels ≥3.0μIU/mL in attempts to improve FOR.

Novel correlates between antimüllerian hormone and menstrual cycle characteristics in African-American women (23-35 years-old)

OBJECTIVE

To characterize normative antimüllerian hormone (AMH) levels and ascertain which factors are associated with AMH in a large cohort of reproductive-age women.

DESIGN

Cross-sectional study.

SETTING

Not applicable.

PATIENT(S)

A total of 1,654 African-American women (AAW) ages 23-34 at recruitment.

INTERVENTION(S)

Not applicable.

MAIN OUTCOME MEASURE(S)

Serum AMH measured using an ultrasensitive ELISA.

RESULT(S)

The median AMH was 3.18 ng/mL, and there was a significant, but nonlinear, relationship between age and AMH, with levels peaking at age 25. As AMH was not normally distributed, log transformation was performed and used for all analyses. In a multivariable age-adjusted model, body mass index, current use of hormonal contraception, and history of a thyroid condition were inversely associated with AMH, while history of abnormal menstrual bleeding and menstrual cycles longer than 35 days were positively associated with AMH.

CONCLUSION(S)

While age is correlated with AMH, it accounts for only a portion of the variation seen. This study adds valuable information to the existing literature on normative AMH levels in young reproductive-age women. While our findings fill a critical data gap for ovarian reserve in AAW, the insights gained will be of benefit for all women.

High prevalence of autoimmune thyroid diseases in patients with prolactinomas: A cross-sectional retrospective study in a single tertiary referral centre

BACKGROUND

Prolactin has been shown to exert potent immunomodulatory activities.

DESIGN

Retrospective cross-sectional study examining the prevalence of autoimmune thyroid diseases (AITD) in patients with prolactinomas. The medical files of 462 patients (367 women and 95 men) followed up at a single tertiary referral centre were analyzed.

RESULTS

The prevalence of AITD among prolactinoma patients was estimated at 21.0% (23.2% in females and 12.6% in males). In 51.5% of the patients, diagnosis of prolactinoma preceded the development of AITD; in 37.2%, both diseases were simultaneously diagnosed and 11.3% of patients were diagnosed first with AITD. Hyperthyroidism was observed in 1.24% of the investigated subjects. Primary hypothyroidism was detected in 15.6% of all patients (16.4% in women; 10.7% in men) with a mean incidence of 24 cases/1000/year.

CONCLUSIONS

Our results demonstrate the high frequency of AITD in patients with prolactinomas. The prevalence rate of hyperthyroidism is comparable with the literature data from community-based studies. In contrast, the prevalence of the spontaneous hypothyroidism due to autoimmune thyroiditis is significantly higher in female and male subgroups of patients with prolactinomas in comparison with the general population. A possible role of supraphysiologically increased prolactin levels in the pathogenesis and the clinical course of AITD in patients with prolactinomas can be suggested. Based on these findings we recommend routine screening for AITD with simple thyroid tests (TSH, TPO-Abs and ultrasound examination) in all patients diagnosed with prolactinoma.

The impact of the presence of antithyroid antibodies on pregnancy outcome following intracytoplasmatic sperm injection-ICSI and embryo transfer in women with normal thyreotropine levels

PURPOSE

The aim of our study was to investigate the impact of anti-thyroid peroxidase antibodies (Anti-TPO) on pregnancy outcome following the in vitro fertilization and embryo transfer (IVF-ET) in general groups and in subgroups divided according to AMH level and age.

METHODS

A total of 114 patients positive for anti-thyroid peroxidase antibodies (Anti-TPO+ group) and 495 infertile women negative for anti-thyroid peroxidase antibodies (Anti-TPO- group) undergoing IVF with ICSI from April 2010 to April 2012 were analyzed retrospectively.

RESULTS

There were no significant differences in age, BMI, basal FSH, LH, AMH levels and duration of infertility between the two main groups. No significant differences in terms of the days of ovarian stimulation, estradiol level in day 8, total gonadotropin dose, number of oocytes retrieved, available embryos and blastocysts, number of embryos transferred nor in rates of fertilization, implantation, clinical pregnancy, live birth and abortion rate between two main groups were found. The only statistically significant difference among the groups with different anti-TPO antibodies levels was found in basal FSH concentration and BMI. Among the clinical outcomes of IVF with respect to the different anti-TPO levels, the only significant difference was found for the number of oocytes retrieved. Analysis of the baseline parameters in relationship to age categories and AMH levels found significant differences between women positive and negative for thyroid antibodies with respect to basal FSH and LH levels for women >37 years and for basal FSH in AMH <0.6 subgroup.

CONCLUSIONS

The present study reveals that patients with anti-TPO antibodies showed no significant differences in fertilization, implantation, pregnancy rates, live birth rates and no higher risk for miscarriage following IVF-ET when compared with those negative for anti-thyroid antibodies.