Thyroid and Fertility: Recent Advances

Subclinical/overt hypothyroidism may be associated with diminished ovarian reserve in infertile women independent of thyroid autoimmunity

Objective

To investigate the association between thyroid dysfunction or thyroid autoimmunity (TAI) and diminished ovarian reserve (DOR).

Methods

A total of 2,867 women undergoing their first in-vitro fertilization (IVF) cycle at Shenzhen Zhongshan Obstetrics & Gynecology Hospital between January 1, 2013 and June 30, 2021, were enrolled in this study. The participants had documented thyroid and ovarian reserve metrics. They were categorized into three groups based on their thyroid function: normal thyroid function (N = 2,540), subclinical/overt hypothyroidism (SCH/OH) (N = 290), and subclinical/overt hyperthyroidism (N = 37). Anti-Mullerian hormone (AMH) and antral follicle count (AFC) were assessed and collected. Women with AMH <1.2 ng/mL and AFC < 5 were diagnosed with DOR. Basic characteristics and ovarian reserve-related parameters were compared among the three groups. The association between thyroid function and ovarian reserve function was further analyzed using logistical regression analyses. In addition, the euthyroid population was stratified using a thyroid-stimulating hormone (TSH) threshold of 2.5 µIU/mL, and the ovarian reserve-related parameters were compared among women with low-normal TSH (TSH < 2.5 µIU/mL), high-normal TSH (2.5 µIU/mL ≤ TSH ≤ 4.2 µIU/mL) and SCH/OH.

Results

Women with SCH/OH had lower AMH levels (2.79 ng/mL vs. 3.41 ng/mL, P < 0.001) and a significantly higher prevalence of AMH level < 1.2ng/mL (17.2% vs. 12.1%, P = 0.015) compared to those with normal thyroid function. The prevalence of DOR was also higher among women with SCH/OH (10.0% vs. 6.5%, P = 0.036). There were no significant differences in ovarian reserve between women with normal thyroid function and those with subclinical/overt hyperthyroidism. Logistic regression analyses showed that the odds ratio (OR) of women with SCH/OH suffering from DOR was 1.666 (95% CI: 1.079-2.572) compared to those with normal thyroid function, after adjusting for TAI status and basic clinical characteristics. When the euthyroid group was stratified according to TSH levels, women with SCH/OH showed significantly lower AMH levels compared to women with low-normal TSH (2.79 ng/mL vs. 3.44 ng/mL, P < 0.001) and a significantly higher prevalence of DOR (10.0% vs. 6.0%, P = 0.010). Logistic regression analyses showed that the women with SCH/OH had an increased prevalence of DOR (OR: 1.819, 95% CI: 1.158-2.858) compared to those with low-normal TSH, after adjusting for TAI status and basic clinical characteristics. However, the OR for DOR among women with high-normal TSH was not significantly elevated compared to those with low-normal TSH (OR: 1.310, 95% CI: 0.936-1.832).

Conclusion

SCH/OH may be associated with DOR, irrespective of TAI status.

Thyroid impairment and male fertility: a narrative review of literature

PURPOSE

To evaluate the effect of thyroid function on male fertility, focusing on hypo- and hyperthyroidism.

METHODS

A PubMed/MEDLINE, Web of Science, and Scopus research was performed. Original studies in English published online up to 31 May 2023 were selected and reviewed. The final reference list was defined based on the relevance of each paper to the scope of this review.

RESULTS

The available data in animals (31 studies) and human (26 studies) showed conflicting results. However, thyroid dysfunction altered erection and ejaculation both in animal models than in men.

CONCLUSION

Both hypothyroidism and hyperthyroidism seem to cause ejaculation and erectile dysfunction. Hence, Guidelines recommend against the systematic screening for thyroid disorders in the men in sub-fertile couples, but only in men with ejaculation and erectile dysfunction and/or altered semen parameters.

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.

Association of a history of depression with infertility, miscarriage and stillbirth: a longitudinal cohort study

AIMS

The role of depression in subsequent infertility, miscarriage and stillbirth remains unclear. This study aimed to examine the association of a history of depression with these adverse outcomes using a longitudinal cohort study of women across their reproductive life span.

METHODS

This study used data from participants in the Australian Longitudinal Study on Women's Health who were born in 1973-1978. Participants (N = 8707) were followed up every 3 years from 2000 (aged 22-27) to 2018 (aged 40-45). Information on a diagnosis of depression was collected from each survey, and antidepressant medication use was identified through pharmaceutical prescription data. Histories of infertility, miscarriage, and stillbirth were self-reported at each survey. Time-lagged log-binomial models with generalized estimating equations were used to assess the association of a history of depression up to and including in a given survey with the risk of fertility issues in the next survey.

RESULTS

Women with a history of depression (excluding postnatal depression) were at higher risk of infertility [risk ratio (RR) = 1.34, 95% confidence interval (CI): 1.21-1.48], miscarriage (RR = 1.22, 95%CI: 1.10-1.34) and recurrent miscarriages (≥2; RR = 1.39, 95%CI: 1.17-1.64), compared to women without a history of depression. There were too few stillbirths to provide clear evidence of an association. Antidepressant medication use did not affect the observed associations. Estimated RRs of depression with infertility and miscarriage increased with age.

CONCLUSIONS

A history of depression was associated with higher risk of subsequent infertility, miscarriage and recurrent miscarriages.

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.

Epigenetic impact of hypothyroidism on the functional differentiation of the mammary gland in rats

Mammary gland (MG) lactogenic differentiation involves epigenetic mechanisms. We have previously shown that hypothyroidism (HypoT) alters the MG transcriptome in lactation. However, the role of thyroid hormones (T3 and T4 a. k.a. THs) in epigenetic differentiation of MG is still unknown. We used a model of post-lactating HypoT rats to study in MG: a) Methylation and expression level of Gata3, Elf5, Stat6, Stat5a, Stat5b; b) Expression of Lalba, IL-4Rα and Ncoa1 mRNA; c) Histone H3 acetylation and d) Estrogen and progesterone concentration in serum. HypoT increases the estrogen serum level, decreases the progesterone level, promotes methylation of Stat5a, Stat5b and Stat6, decreasing their mRNA level and of its target genes (Lalba and IL-4Rα) and increases the Ncoa1 mRNA expression and histone H3 acetylation level. Our results proved that HypoT alters the post-lactation MG epigenome and could compromise mammary functional differentiation.

Effect of anti-thyroid antibodies on recurrent miscarriage: A meta-analysis

SETTING

Previous studies addressed the association between anti-thyroid antibodies and recurrent miscarriage (RM), however, the role of anti-thyroid antibodies in RM patients is debatable.

OBJECTIVES

Therefore, we conducted this meta-analysis and the aim of this current study was to assess whether anti-thyroid peroxidase (anti-TPO) and/or anti-thyroglobulin (anti-TG) antibody positivity was associated with RM.

DESIGN

A meta-analysis was conducted.

PARTICIPANTS

Recurrent miscarriage patients.

METHODS

STATA 12.0 software were applied to compute odds ratios (ORs)/relative risks (RRs) and 95% CIs regarding association between anti-TPO and anti-TG antibodies and the prevalence of RM.

RESULTS

N = 28 studies (8875 participants) explored effect of anti-thyroid antibodies on RM. Analysis of the 28 studies revealed significant association between anti-TPO, anti-TG antibodies and the prevalence of RM with a random effects model (OR/RR = 2.02; 95% CI: 1.63-2.51, p < 0.001; I2 = 44.3%, p value for Q test = 0.004). Analysis of the 20 studies revealed significant association between anti-TPO antibodies and the prevalence of RM with a random effects model (OR/RR = 1.59; 95% CI: 1.25-2.03, p < 0.001; I2 = 43.1%, p value for Q test = 0.022). Analysis of the 14 studies revealed significant association between anti-TG antibodies and the prevalence of RM with a random effects model (OR/RR = 2.25; 95% CI: 1.56-3.23, p < 0.001; I2 = 49.2%, p value for Q test = 0.019).

CONCLUSIONS

Based on the currently available analysis, our findings suggest that women with anti-TPO and/or anti-TG antibodies have a higher risk of RM than that in negative antibody women. Further investigation is needed to better clarify the exact role of the anti-thyroid antibodies in RM and whether treatment is of benefit.

LIMITATIONS

First, differences from various detection methods and reagents used in different studies may affect the diagnostic interpretation of anti-thyroid antibodies, which might influence the accuracy of this meta-analysis. Second, positive anti-thyroid antibodies seem likely to be part of a more general disorder of maternal immune system, due to restrictions of funding and condition, a complete autoantibody screening investigation is hardly to conduct in all participants, and this could be a possible limitation of all included studies. Third, there is no mention of thyroxine therapy on RM, making the meta-analysis even more limited.

Is thyroid function associated with polycystic ovary syndrome? A bidirectional Mendelian randomization study

OBJECTIVE

Some observational studies have suggested the association between thyroid function and polycystic ovary syndrome (PCOS). However, it remains to be determined whether these associations are causal or not. The aim of this study was to investigate the underlying causal association between different thyroid function status and PCOS.

METHODS

Bidirectional Mendelian randomization (MR) analysis was conducted to explore the impact of different thyroid function statuses on PCOS. The study included 10,074 individuals with PCOS and 103,164 controls for the primary analysis, with validation analysis repeated in the FinnGen R9 and EstBB PCOS cohorts. Female-specific thyroid function GWAS data were obtained from European population, including Hyperthyroidism (22,383 cases and 54,288 controls) and Hypothyroidism (27,383 cases and 54,288 controls) from the UK Biobank, and TSH (54,288 cases and 72,167 controls) and FT4 (49,269 cases and 72,167 controls) within the reference range from the ThyroidOmics Consortium. Inverse variance weighting (IVW) was chosen as the principal method, and sensitivity analysis was conducted to test for the presence of horizontal pleiotropy or heterogeneity.

RESULTS

The IVW analysis indicated nominal significance between normal TSH levels and PCOS after adjusted for age and BMI [OR (95% CI) = 0.78(0.62,0.97), P = 0.029], suggesting that maintaining normal TSH levels might act as a protective factor against the pathogenesis of PCOS. Besides, in order to increase the statistical power, we pooled PCOS GWAS above together by meta-analysis and found PCOS contributed to the occurrence of hyperthyroidism [OR(95%CI) = 1.37(0.73,2.57), P = 0.012]. However, no causal relationship was found after Bonferroni correction (P-value < 0.0031).

CONCLUSION

Although the MR analysis didn't indicate genetic causal association between thyroid function and PCOS after Bonferroni correction. Further efforts are needed to interpret the potential causal relationship between thyroid function and PCOS in different age and BMI subgroup.

Association between per- and polyfluoroalkyl substances exposure and thyroid function biomarkers among females attending a fertility clinic

Per- and polyfluoroalkyl substances (PFAS) exposure was associated with changes in thyroid function in pregnant mothers and the general population. Limited such evidence exists in other susceptible populations such as females with fertility problems. This cross-sectional study included 287 females seeking medically assisted reproduction at a fertility clinic in Massachusetts, United States, between 2005 and 2019. Six long-alkyl chain PFAS, thyroid hormones, and autoimmune antibodies were quantified in baseline serum samples. We used generalized linear models and quantile g-computation to evaluate associations of individual PFAS and their total mixture with thyroid biomarkers. Most females were White individuals (82.7%), had graduate degrees (57.8%), and nearly half had unexplained subfertility (45.9%). Serum concentrations of all examined PFAS and their mixture were significantly associated with 2.6%-5.6% lower total triiodothyronine (TT3) concentrations. Serum concentrations of perfluorononanoate (PFNA), perfluorodecanoate (PFDA), and perfluoroundecanoate (PFUnDA), and of the total mixture were associated with higher ratios of free thyroxine (FT4) to free triiodothyronine (FT3). No associations were found for PFAS and TSH or autoimmune antibodies. Our findings support the thyroid-disrupting effect of long alkyl-chain PFAS among a vulnerable population of subfertile females.

Disruption of Thyroid Hormone Receptor Thrab Leads to Female Infertility in Zebrafish

Thyroid hormones (THs) T4 and T3 are vital for development, growth, and metabolism. Thyroid dysfunction can also cause problems in fertility, suggesting involvement of THs in reproduction. In zebrafish, there exist 2 forms of TH receptor alpha gene (thraa and thrab). Disruption of these genes by CRISPR/Cas9 showed no reproductive irregularities in the thraa mutant; however, inactivation of the thrab gene resulted in female infertility. Although young female mutants (thrabm/m) showed normal ovarian development and folliculogenesis before sexual maturation, they failed to release eggs during oviposition after sexual maturation. This spawning failure was due to oviductal blockage at the genital papilla. The obstruction of the oviduct subsequently caused an accumulation of the eggs in the ovary, resulting in severe ovarian hypertrophy, abdominal distention, and disruption of folliculogenesis. Gene expression analysis showed expression of both TH receptors and estrogen receptors in the genital papilla, suggesting a direct TH action and potential interactions between thyroid and estrogen signaling pathways in controlling genital papilla development and function. In addition to their actions in the reproductive tracts, THs may also have direct effects in the ovary, as suggested by follicle atresia and cessation of folliculogenesis in the heterozygous mutant (thrab+/m), which was normal in all aspects of female reproduction in young and sexually mature fish but exhibited premature ovarian failure in aged females. In summary, this study provides substantial evidence for roles of THs in controlling the development and functions of both reproductive tract and ovary.

Minerals and the Menstrual Cycle: Impacts on Ovulation and Endometrial Health

The role of minerals in female fertility, particularly in relation to the menstrual cycle, presents a complex area of study that underscores the interplay between nutrition and reproductive health. This narrative review aims to elucidate the impacts of minerals on key aspects of the reproductive system: hormonal regulation, ovarian function and ovulation, endometrial health, and oxidative stress. Despite the attention given to specific micronutrients in relation to reproductive disorders, there is a noticeable absence of a comprehensive review focusing on the impact of minerals throughout the menstrual cycle on female fertility. This narrative review aims to address this gap by examining the influence of minerals on reproductive health. Each mineral's contribution is explored in detail to provide a clearer picture of its importance in supporting female fertility. This comprehensive analysis not only enhances our knowledge of reproductive health but also offers clinicians valuable insights into potential therapeutic strategies and the recommended intake of minerals to promote female reproductive well-being, considering the menstrual cycle. This review stands as the first to offer such a detailed examination of minerals in the context of the menstrual cycle, aiming to elevate the understanding of their critical role in female fertility and reproductive health.

The impact of thyroid autoimmunity on pregnancy outcomes in women with unexplained infertility undergoing intrauterine insemination: a retrospective single-center cohort study and meta-analysis

Introduction

Infertility affects 8-12% of couples worldwide, with 15-30% classified as unexplained infertility (UI). Thyroid autoimmunity (TAI), the most common autoimmune disorder in women of reproductive age, may impact fertility and pregnancy outcomes. However, the underlying mechanism is unclear. This study focuses on intrauterine insemination (IUI) and its potential association with TAI in UI patients. It is the first meta-analysis following a comprehensive literature review to improve result accuracy and reliability.

Methods

Retrospective cohort study analyzing 225 women with unexplained infertility, encompassing 542 cycles of IUI treatment. Participants were categorized into TAI+ group (N=47, N= 120 cycles) and TAI- group (N=178, N= 422 cycles). Additionally, a systematic review and meta-analyses following PRISMA guidelines were conducted, incorporating this study and two others up to June 2023, totaling 3428 IUI cycles.

Results

Analysis revealed no significant difference in independent variables affecting reproductive outcomes. However, comparison based on TAI status showed significantly lower clinical pregnancy rates (OR: 0.43, P= 0.028, 95%CI: 0.20-0.93) and live birth rate (OR: 0.20, P= 0.014, 95%CI: 0.05 ~ 0.71) were significantly lower than TAI- group. There was no significant difference in pregnancy rate between the two groups (OR: 0.61, P= 0.135, 95%CI: 0.32-1.17). However, the meta-analysis combining these findings across studies did not show statistically significant differences in clinical pregnancy rates (OR:0.77, P=0.18, 95%CI: 0.53-1.13) or live birth rates (OR: 0.68, P=0.64, 95%CI: 0.13-3.47) between the TAI+ and TAI- groups.

Discussion

Our retrospective cohort study found an association between TAI and reduced reproductive outcomes in women undergoing IUI for unexplained infertility. However, the meta-analysis incorporating other studies did not yield statistically significant associations. Caution is required in interpreting the relationship between thyroid autoimmunity and reproductive outcomes. Future studies should consider a broader population and a more rigorous study design to validate these findings. Clinicians dealing with women with unexplained infertility and TAI should be aware of the complexity of this field and the limitations of available evidence.

Evaluating the progression to abnormal thyrotropin in euthyroid preconception women: a population-based study

BACKGROUND

Abnormal preconception thyrotropin levels were associated with fecundability and adverse fetomaternal outcomes, however, little is known regarding the natural change of serum thyrotropin in euthyroid preconception women. Thus, we performed a population-based study to evaluate the progression to abnormal thyrotropin in euthyroid preconception women.

METHODS

This retrospective cohort study used data from the National Free Prepregnancy Checkups Project (NFPCP) collected between 2010 and 2020. Female Han Chinese participants aged 20-49 years who had two repeated NFPCP participations with a time interval of 1.5-3.0 years, confirmed non-pregnant status within this duration, and normal thyrotropin levels during their first participation were included for the analysis of thyrotropin abnormalities during the second NFPCP examination. Data were analyzed between June 1 and October 1, 2023.

RESULTS

This study included 186,095 euthyroid women of reproductive age (mean ± SD, 26.72 ± 4.70 years) whose preconception thyrotropin levels were between 0.37 and 4.87 mIU/L. The median follow-up time was 2.13 (IQR, 1.85-2.54) years. A total of 8,497 (4.57%) women developed abnormal thyrotropin, including 4,118 (2.21%) subnormal thyrotropin and 4,379 (2.35%) supranormal thyrotropin. Compared with the reference group (thyrotropin 1.01-2.00 mIU/L), the lower baseline thyrotropin group had greater risk of developing subnormal thyrotropin, and the higher baseline thyrotropin group had greater risk of developing supranormal thyrotropin. Moreover, the restricted cubic spline analysis revealed a U-shaped dose-response association of baseline thyrotropin levels or thyrotropin multiples of the median (MOM) levels against risk of subnormal thyrotropin in the follow-up, and a J-shaped dose-response association against risk of supranormal thyrotropin levels in the follow-up. We further found that baseline thyrotropin outside of 1.43-1.93 mIU/L or baseline thyrotropin MOM outside 0.59-1.36 would hava a higher risk of developing of abnormal thyrotropin.

CONCLUSIONS

Both low and high baseline thyrotropin were associated with a significantly increased risk of developing abnormal thyrotropin outcomes. The optimal preconception baseline thyrotropin levels may be between 1.43 mIU/L and 1.93 mIU/L or baseline thyrotropin MoM between 0.59 and 1.36 to minimize progression toward abnormal thyrotropin after 1.5-3.0 years. These findings may help with counseling of preconception thyroid function monitoring.

Elevated TSH Levels: A Database Study of General Practitioners' Course of Action

OBJECTIVE

To investigate general practitioners' course of action after detection of elevated thyroid stimulating hormone (TSH) levels regarding repeat testing, direct levothyroxine replacement, or neither.

METHODS

We conducted a retrospective study of adults without prior evidence of thyroid disease and with a first detection of elevated TSH levels from January 1, 2015, to December 31, 2020, using data from electronic medical records of a Swiss primary care database. We determined the occurrence of either repeat TSH testing or direct levothyroxine initiation in primary care during 12-month follow-up and determined associations with demographic and clinical factors.

RESULTS

Of the 1 591 patients included (median age 65 years, 64.4% female, median TSH 5.7 mIU/L), 34.3% received repeat TSH testing and 12.4% received direct levothyroxine replacement in primary care during follow-up. Repeat TSH testing showed the strongest association with overt hypothyroidism and was more common among patients with high primary care utilization and among patients aged 40-64 years compared to patients aged <40 years. Direct levothyroxine initiation was more likely for TSH levels >7 mIU/L, overt hypothyroidism, female patients, and nonurban practices.

CONCLUSIONS

While the degree of thyroid dysfunction was the main driver of follow-up, we identified important gaps in the primary care-based monitoring of elevated TSH levels in young patients and in patients with infrequent consultations. We also observed potential overtreatment of women and patients in nonurban areas. Our findings highlight the need for standardization and dissemination of guidelines for the management of elevated TSH levels among general practitioners.

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.

Thyroid dysfunction and female infertility. A comprehensive review

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Impact of thyroid autoimmunity on pregnancy outcomes in euthyroid patients with recurrent implantation failure

RESEARCH QUESTION

Does thyroid autoimmunity (TAI) adversely affect pregnancy outcomes after IVF/intracytoplasmic sperm injection (ICSI) in euthyroid patients with recurrent implantation failure (RIF)?

DESIGN

This retrospective cohort study was conducted at the Reproductive Hospital Affiliated with Shandong University from November 2016 to September 2021. A total of 1031 euthyroid patients diagnosed with RIF were enrolled. Based on serum thyroid autoantibody concentrations, the participants were divided into two groups: the TAI-positive group (219 women with RIF) and the TAI-negative group (812 women with RIF). The parameters were compared between the two groups. Additionally, logistic regression was used to adjust related confounders for primary outcomes, and subgroup and stratified analyses were performed according to different thyroid autoantibody types and TSH concentrations.

RESULTS

There was no significant difference in ovarian reserve, ovarian response, embryo quality, pregnancy outcome or neonatal outcome between the two groups (P > 0.05). After adjustments for age, body mass index, thyroid-stimulating hormone and free thyroxine, the biochemical pregnancy rate in the TAI-positive group was significantly lower than that in the TAI-negative group (odds ratio 1.394, 95% CI 1.023-1.901, adjusted P = 0.036). Regarding the implantation rate, clinical pregnancy rate, pregnancy loss rate, stillbirth rate and live birth rate, no significant differences were observed even with subgroup and stratified analyses (P > 0.05).

CONCLUSIONS

TAI had no impact on pregnancy outcomes in euthyroid RIF patients who underwent IVF/ICSI. In clinical practice, interventions targeting thyroid autoantibodies in these patients should be implemented with caution and additional evidence is needed.

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.

A novel machine learning model for predicting clinical pregnancy after laparoscopic tubal anastomosis

BACKGROUND

Laparoscopic tubal anastomosis (LTA) is a treatment for women who require reproduction after ligation, and there are no reliable prediction models or clinically useful tools for predicting clinical pregnancy in women who receive this procedure. The prediction model we developed aims to predict the individual probability of clinical pregnancy in women after receiving LTA.

METHODS

Retrospective analysis of clinical data of patients undergoing LAT in the Second Hospital of Lanzhou University from July 2017 to December 2021. Least absolute shrinkage and selection operator (LASSO) regression was used for data dimension reduction and feature selection. We incorporated the patients' basic characteristics, preoperative laboratory tests and laparoscopic tubal anastomosis procedure signature and obtained a nomogram. The model performance was evaluated in terms of its calibration, discrimination, and clinical applicability. The prediction model was further internally validated using 200 bootstrap resamplings.

RESULTS

A total of 95 patients were selected to build the predictive model for clinical pregnancy after LTA. The LASSO method identified age, intrauterine polyps, pelvic adhesion and thyroid stimulating hormone(TSH) as independent predictors of the clinical pregnancy rate. The prediction nomogram included the abovementioned four predictive parameters. The model showed good discrimination with an area under the curve (AUC) value of 0.752. The Hosmer‒Lemeshow test of calibration showed that χ2 was 4.955 and the p value was 0.838, which indicates a satisfactory goodness-of-fit. Decision curve analysis demonstrated that the nomogram was clinically useful. Internal validation shows that the predictive model performs well.

CONCLUSION

This study presents a nomogram incorporating age, intrauterine polyps, pelvic adhesion and TSH based on the LASSO regression model, which can be conveniently used to facilitate the individualized prediction of clinical pregnancy in women after LTA.

The Impact of Systemic Oncological Treatments on the Fertility of Adolescents and Young Adults-A Systematic Review

BACKGROUND

Over the past decades, advancements in oncological treatments have led to major improvements in survival. Particularly for adolescents and young adults (AYAs), fertility is an important concern in cancer survivorship. The purpose of the review is to provide physicians with a practical overview of the current knowledge about the impact of systemic oncological treatments on the fertility of female and male AYAs.

METHODS

A systematic review was performed based on relevant articles obtained from 4 databases up until 31 December 2022.

RESULTS

The mechanisms of gonadotoxicity and the concurrent risk is described for the following categories: chemotherapy, targeted therapy and immunotherapy. For the category "chemotherapy", the specific effects and risks are listed for the different classes and individual chemotherapeutics. In the category "targeted therapy", a distinction was made between tyrosine kinase inhibitors (TKIs) and monoclonal antibodies. Information concerning immunotherapy is scarce.

CONCLUSIONS

The effects of chemotherapy on fertility are well investigated, but even in this category, results can be conflicting. Insufficient data are available on the fertility effects of targeted therapy and immunotherapy to draw definitive conclusions. More research is needed for these therapies and their evolving role in treating cancers in AYAs. It would be useful to include fertility endpoints in clinical trials that evaluate new and existing oncological treatments.

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.

The association between hypothyroidism and perinatal outcomes in patients with polycystic ovary syndrome

PURPOSE

To compare pregnancy, delivery, and neonatal outcomes in patients with polycystic ovary syndrome (PCOS) with and without concomitant hypothyroidism.

METHODS

A retrospective population-based cohort study including all women with an ICD-9 diagnosis of PCOS in the US between 2004 and 2014, who delivered in the third trimester or had a maternal death. We compared women with a concomitant diagnosis of hypothyroidism to those without. Women with hyperthyroidism were excluded. Pregnancy, delivery, and neonatal outcomes were compared between the two groups.

RESULTS

Overall, 14,882 women met inclusion criteria. Among them, 1882 (12.65%) had a concomitant diagnosis of hypothyroidism, and 13,000 (87.35%) did not. Women with concomitant hypothyroidism, compared to those without, were characterized by increased maternal age (25.5% ≥ 35 years vs. 18%, p < 0.001, respectively), and had a higher rate of multiple gestations (7.1% vs. 5.7%, p = 0.023). Interestingly, pregnancy, delivery and neonatal outcomes were comparable between the groups, except for a higher rate of small-for-gestational-age (SGA) neonates in the group with hypothyroidism (4.1% vs. 3.2%, p = 0.033) (Tables 2 and 3). In a multivariate logistic regression adjusting for potential confounders, hypothyroidism was no longer found to be associated with SGA (adjusted odds ratio [aOR] 1.32, 95% confidence interval [CI] 0.99-1.75, p = 0.057), but was found to increase the odds for preeclampsia (aOR 1.30, 95% CI 1.06-1.59, p = 0.012).

CONCLUSIONS

In patients with PCOS, concomitant hypothyroidism significantly increases the risk for preeclampsia. Unexpectedly, other pregnancy complications commonly increased by hypothyroidism were not increased in women with PCOS, likely due to the inherent elevated baseline pregnancy risks of PCOS.

Infertility and Pregnancy Rates in Female Thyroid Cancer Survivors: A Retrospective Cohort Study Using Health Care Administrative Data from Israel

Background: Thyroid cancer (TC) is one of the most common carcinomas in young women. Concerns have been raised regarding the impact of the disease and its treatment on reproductive function. The aim of the study was to investigate the association of TC diagnosis and radioactive iodine (RAI) treatment on infertility and pregnancy rates in women. Methods: The comprehensive computerized database of a health management organization in Israel was screened for all female patients who were diagnosed with TC at age ≤40 years in 2000-2020. Rates of infertility (based on a documented diagnosis or purchase of fertility medications in the patient files) and pregnancy were compared with healthy age-matched controls. Results: The cohort included 1164 patients with TC (median age at diagnosis 31.6 years; interquartile range [IQR]: 26.7-35.4) and 5030 controls, followed for a median period of 10 years (IQR: 5.0-15.0). The infertility rate was higher in the TC group than in the control group (23.9% vs. 20.4%, p = 0.008). Still, the postdiagnosis/referent date pregnancy rates were comparable in the whole cohort (46.9/47.7%, p = 0.625) and across all age quartiles. The median time to the first pregnancy postdiagnosis/referent date was longer in TC patients than in controls (37 vs. 31 months, p < 0.001). Within the TC group, women who received repeated radioactive iodine treatment (n = 611, 52.5%) had comparable rates of infertility and pregnancy as those who did not. However, their time to the first postdiagnosis pregnancy was longer (median 45 vs. 29 months, p = 0.020). Conclusions: Our study provides reassuring evidence about the reproductive characteristics of women treated for TC. Pregnancy rates in TC survivors were comparable with controls. However, a higher infertility rate and a longer time to conceive were observed in the TC group compared with the control group. These findings were consistent in women who received single or repeated RAI treatments.

The role of thyroid function in female and male infertility: a narrative review

PURPOSE

We herein aimed to review the new insights into the impact of impaired thyroid function on male and female fertility, spacing from spontaneous pregnancy to ART, with the objective of providing an updated narrative revision of the literature.

METHODS

This narrative review was performed for all available prospective, retrospective and review articles, published up to 2021 in PubMed. Data were extracted from the text and from the tables of the manuscript.

RESULTS

Thyroid dysfunction is frequently associated with female infertility, whereas its link with male infertility is debated. Female wise, impaired function is detrimental to obstetric and fetal outcomes both in spontaneous pregnancies and in those achieved thanks to assisted reproduction technologies (ART). Furthermore, the reference range of TSH in natural pregnancy and ART procedures has recently become a matter of debate following recent reports in this field. On the other hand, the impact of thyroid function on the male reproductive system is less clear, although a possible role is suggested via modulation of Sertoli and Leydig cells function and spermatogenesis.

CONCLUSION

Thyroid function should be carefully monitored in both male and female, in couples seeking spontaneous pregnancy as well as ART, as treatment is generally immediate and likely to improve chances of success.

Comparison between cutting versus retraction of anterior cervical musculature during endoscopic thyroidectomy

To compare the different techniques of managing the anterior cervical muscle group during endoscopic thyroidectomy via the trans-thoraco-areolar approach. A total of 90 patients with thyroid tumors less than 3 cm were evaluated. The time for each intraoperative step, total surgery duration, intraoperative blood loss volume, pathology results, number of lymph nodes dissected and patient satisfaction with esthetics were assessed. Intraoperative blood loss volume, drainage volume on the first postoperative day, number of lymph nodes dissected in the central region, postoperative hospitalization duration, number of transient laryngeal nerve palsy cases, and number of transient hypocalcemia cases were similar between the muscle transection (MT) and muscle retraction (MR) groups. The MT group had significantly higher postoperative pain scores after 12 hours, but pain scores at 48 hours postoperatively were not significantly different between the 2 groups. In the unilateral thyroidectomy subgroup, the durations of isthmus resection, freeing the lateral thyroid, exposing the laryngeal recurrent nerve, and management of the inferior pole were similar for both muscle management methods. The muscle dissection and suture time was significantly longer for the MT group than that for the MR group; in contrast, the upper pole management time of the muscle resection group was significantly shorter. In the bilateral resection subgroup, both muscle management methods required similar durations for managing the contralateral upper pole after ipsilateral thyroidectomy. However, intraoperative blood loss was significantly higher for MR than for MT, while postoperative pain was relatively mild. In the malignant tumor subgroup, duration of inferior thyroid pole management was significantly less for MT than for MR. There are significant differences between the 2 muscle management methods in handling and suturing muscles. Both methods have satisfactory postoperative outcomes for resection of thyroid nodules with diameters ≤3 cm. For tumors located in the upper pole, transection of the anterior cervical muscles confers higher feasibility of the thyroidectomy technique; however, suturing becomes difficult in such scenarios.

Delayed entry into prenatal care among women with pre-pregnancy health conditions, National Birth Defects Prevention Study, 1997-2011

First trimester entry into prenatal care is recommended for all women, and especially women with pre-pregnancy conditions. Our objective was to determine whether women with pre-pregnancy conditions were at lower risk of entry after the first trimester (delayed entry) into prenatal care than women without a pre-pregnancy health condition. We used data from 10,890 participants in the National Birth Defects Prevention Study who delivered liveborn infants without birth defects. Women reported pre-pregnancy conditions and timing of entry into prenatal care during a computer-assisted telephone interview. Multivariable logistic regression analyses were conducted to evaluate whether having a pre-pregnancy condition was associated with delayed entry into prenatal care compared to women without pre-pregnancy conditions. Approximately 13% of women reported delayed entry into prenatal care, and 18% of women reported a pre-pregnancy condition. Delayed entry into prenatal care was not associated with pre-pregnancy cardiometabolic or neurologic conditions. Women with thyroid conditions were less likely to report delayed entry into prenatal care (prevalence odds ratio (OR), 95% confidence interval (CI): 0.55 [0.32, 0.94]), but women with hematologic and respiratory conditions were more likely to report delayed entry into prenatal care (OR: 1.95 [1.00, 3.82] and 1.27 [0.95, 1.72], respectively), compared to those without any chronic conditions. Future research investigating the success of early prenatal care among women with thyroid conditions could identify ways to reduce delayed prenatal care among women with other pre-pregnancy conditions.

Pre-Conceptional Anti-Thyroid Antibodies and Thyroid Function in Association with Natural Conception Rates

Thyroid functioning is an integral part of the endocrine system that supports conception and pregnancy. Frequent consumption of seafood and iodine by Japanese people may adversely affect their thyroid function. Thus, in this study, we aimed to analyze the associations between iodine intake, thyroid hormones, autoimmunity, and natural conception rates in Japanese women trying to conceive their first child. A prospective study of 24 weeks targeted 80 women with no history of infertility, who did not plan to undergo fertility treatment. Concentrations of urinary iodine concentration and thyroid biomarkers in the serum at enrollment were measured. Thirty-five women naturally conceived during the follow-up. The median (inter-quartile range) urinary concentration of iodine was 297 (165, 500) μg/L. Free triiodothyronine (T3) and free thyroxin (T4) negatively correlated with urinary iodine concentrations. Women with anti-thyroid peroxidase (anti-TPO) ≥ 16 IU/mL had lower conception rates (hazard ratio: 0.28, 95% confidence interval, 0.08-0.92) compared with those with anti-TPO < 16 IU/mL, after adjusting for age and coital frequency. None of anti-thyroglobulin antibody, free T3, free T4, or thyroid-stimulating hormone showed significant associations with conception rate after adjusting for age and coital frequency. The negative association between thyroid autoimmunity and natural conception rates warrants further investigation.

Clinical characteristics and surgical management of endometriosis-associated infertility: A multicenter prospective cohort study

OBJECTIVE

To study clinical, surgical characteristics and the relationship between endometriosis lesion types and conception rate after surgery in infertile women with endometriosis.

METHODS

A prospective, multicenter cohort of 204 women (age 20-35 years) with endometriosis was followed up post-surgery between November 2017 and February 2020 at three tertiary-care hospitals.

RESULTS

Based on the severity of endometriosis lesion type, deep infiltrating endometriosis (DIE) (81/204, 39.7%) was the most common lesion; followed by ovarian endometriosis (OMA) (64/204, 31.4%), and superficial peritoneal endometriosis (SUP) (59/204, 28.9%). Endometriosis patients had a single lesion type (94/204, 46.1%), two lesion types (77/204, 37.7%), or three lesion types (33/204, 16.2%) with significant differences between regions (P < 0.001). Around 40% (37/95) of obese women had SUP (P = 0.003) whereas 78% (14/18) of underweight women had DIE (P < 0.001). Significant differences in mean Endometriosis Fertility Index scores between endometriosis lesion types and patients with one, two, and three types of lesions were observed (P < 0.001). The majority (22/32, 68.8%) of the women conceived naturally after the surgery. Half (16/32; 50%) of the women with a single lesion type conceived after the surgery; of which most (13/16, 81.2%) had SUP, followed by OMA (2/16, 12.5%), and DIE (1/16, 6.3%).

CONCLUSION

Women with SUP and only one type of endometriotic lesion were more likely to conceive post-surgery.

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.

Association of Preconception Thyrotropin Levels With Fecundability and Risk of Spontaneous Abortion in China

IMPORTANCE

Abundant evidence suggests thyroid dysfunction is associated with adverse pregnancy outcomes. However, associations of preconception thyrotropin levels outside of reference range with reproductive health outcomes are not well characterized.

OBJECTIVE

To evaluate the associations of preconception thyrotropin levels with time to pregnancy (TTP) and risk of spontaneous abortion (SA).

DESIGN, SETTING, AND PARTICIPANTS

This population-based cohort study used data from the Chinese National Free Prepregnancy Checkups Project. Female participants aged 20 to 49 years who were trying to conceive were enrolled between January 1, 2013, and December 31, 2016, for the analysis of TTP or SA. Data were analyzed between August 1, 2020, and July 5, 2021.

EXPOSURES

Levels of thyrotropin within 1 year prior to pregnancy.

MAIN OUTCOMES AND MEASURES

The main outcomes were TTP, assessed using hazard ratios (HRs), and SA, assessed using odds ratios (ORs), according to preconception thyrotropin levels. Thyrotropin dose-response associations were assessed using restricted cubic spline regression.

RESULTS

Among 11 194 002 female participants (mean [SD] age, 27.56 [5.10] years) in the TTP cohort, 4 739 421 (42.34%) participants became pregnant within 1 year. Both low and high preconception thyrotropin levels were associated with delayed TTP compared with thyrotropin levels of 0.37 to 2.49 mIU/L (thyrotropin <0.10 mIU/L: HR, 0.90; 95% CI, 0.89-0.92; thyrotropin 4.88-9.99 mIU/L: HR, 0.86; 95% CI, 0.86-0.87; thyrotropin ≥10.00 mIU/L: HR, 0.78; 95% CI, 0.77-0.79). In the SA analysis cohort including 4 678 679 pregnancies, 108 064 SA events (2.31%) were documented. High thyrotropin groups showed an increased risk of SA compared with the group with thyrotropin levels of 0.37 to 2.49 mIU/L (thyrotropin 4.88-9.99 mIU/L: OR, 1.33; 95% CI, 1.28-1.38; thyrotropin ≥10.00 mIU/L: OR, 1.25; 95% CI, 1.14-1.36). Preconception thyrotropin levels showed an inverted J-shaped dose-response association with TTP (χ2 = 311.29; nonlinear P < .001) and a J-shaped dose-response association with SA (χ2 = 58.29; nonlinear P < .001).

CONCLUSIONS AND RELEVANCE

In this cohort study, preconception thyrotropin levels outside of reference range were associated with increased risk of reduced fecundity and SA. These findings may provide insights for the implementation of preconception thyroid function screening and the design of future levothyroxine supplementation trials.

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.

Immune Checkpoint Inhibitors for the Treatment of Gestational Trophoblastic Neoplasia: Rationale, Effectiveness, and Future Fertility

OPINION STATEMENT

Most individuals with gestational trophoblastic neoplasia (GTN) are cured with chemotherapy; however, about 5% of them will develop chemotherapy-resistant disease and will die of disease progression. Most GTN tissues express programmed death ligand-1 (PDL-1), making immune checkpoint inhibitors (ICIs) targeting this pathway an attractive treatment option for individuals with GTN. There is increasing evidence to support the use of ICIs for individuals with recurrent or resistant GTN, but available data are derived from case reports and small single arm trials. As promising as it seems, not all individuals with GTN respond to ICIs, and there is lack of evidence toward which factors mediate the effect of ICIs on GTN. In addition, treatment-related adverse events and impact on future fertility are not negligible and should be considered before initiating this treatment. Therefore, additional research is needed to evaluate treatment outcome of ICIs in GTN compared to standard treatment, and to identify molecular and clinical predictors for treatment response, before this treatment is incorporated into the standard of care.

IVF/ICSI outcomes of euthyroid infertile women with thyroid autoimmunity: does treatment with aspirin plus prednisone matter?

Background

Thyroid autoimmunity (TAI) has been demonstrated to be associated with adverse pregnancy including recurrent miscarriage, unexplained infertility, and implantation failure. To settle with the fertility problem, prescribing aspirin combined with prednisone (P + A) to women positive for anti-thyroid antibodies is frequent in clinical practice, but the underlying effect remains controversial.

Methods

A multicenter, retrospective study was conducted in three reproductive centers from 2017 to 2020. A total of 494 euthyroid infertile women were recruited who were positive for anti-thyroperoxidase and/or thyroglobulin antibodies (TPOAb and TgAb, respectively) with thyroid-stimulating hormone (TSH) levels ranging 0.35-4.0mIU/L and underwent their first in vitro fertilization and embryo transfer (IVF-ET) cycle. Ultimately, 346 women were included of which 150 women were treated with prednisone (10 mg/d) and aspirin (100 mg/d). The remaining 196 women were untreated (control group). Treatment started on the day of embryo transfer and continued until clinical pregnancy was determined.

Results

The clinical pregnancy rate was 57.5% vs. 63.5% in the control and treated groups (P = 0.414) for first fresh embryo transfer cycles and 57.8% vs. 61.8% for frozen-thawed embryo transfer cycles (P = 0.606). In addition, the live birth rate for the fresh embryo transfer was 49.6% vs. 47.3% in the control and treated groups (P = 0.762). Logistic regression revealed that aspirin plus prednisone did not improve the clinical pregnancy rate or miscarriage rate. Furthermore, it was observed that low free triiodothyronine (FT3) was associated with high miscarriage rates.

Conclusions

Utilizing an adjuvant treatment of P + A after the embryo transfer may not be necessary in euthyroid women with thyroid autoimmunity undergoing their first IVF-ET, regardless of the embryo type (fresh or frozen).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04532-2.

Impact of Thyroid Function on Pregnancy and Neonatal Outcome in Women with and without PCOS

Background: Women with polycystic ovary syndrome (PCOS) are more prone to autoimmune thyroiditis, and both disorders lead to subfertility and pregnancy-related complications. The aim of this study was to investigate whether mothers with and without PCOS and their offspring have comparable thyroid parameters at term and how thyroid parameters are associated with perinatal outcome in this population. Methods: This cross-sectional observational study was performed in a single academic tertiary hospital in Austria. Seventy-nine pregnant women with PCOS and 354 pregnant women without PCOS were included. Blood samples were taken from the mother and cord blood at birth. Primary outcome parameters were maternal and neonatal thyroid parameters at delivery. Secondary outcome parameters were the composite complication rate per woman and per neonate. Results: Thyroid dysfunction was more prevalent among PCOS women (p < 0.001). At time of birth, free triiodothyronine (fT3) levels were significantly lower in PCOS than in non-PCOS women (p = 0.005). PCOS women and their neonates had significantly higher thyreoperoxidase antibody (TPO-AB) levels (p = 0.001). Women with elevated TPO-AB had a significantly higher prevalence of hypothyroidism (p < 0.001). There was a significant positive correlation between maternal and neonatal free thyroxine, fT3 and TPO-AB levels. There were no significant differences in thyroid parameters between women or neonates with or without complications. Conclusions: Our results demonstrate a higher prevalence of thyroid dysfunction and autoimmunity in PCOS women, supporting a common etiology of both disorders. We were not able to show an association between complication rate and thyroid parameters.

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.

Thyroid autoimmunity and reproduction: Bidirectional relationship that continues to intrigue

Today, infertility is not only a serious health but also a psycho-social problem, one that is on the rise in the world. Thyroid autoimmunity (TAI) is the most common disease of the thyroid gland in the reproductive period, which can affect spontaneous conception as well as conception through assisted reproduction technology (ART), but also the maintenance of healthy pregnancy. It can also cause numerous maternal and fetal complications. There is a wide array of publications on the topic of the mechanisms of association between TAI and reproduction, with the question of whether thyroid autoantibodies are solely tissue-specific antibodies, whether and when to start levothyroxine treatment, and that we require more fundamental research on the direct effect of thyroid autoantibodies starting from folliculogenesis to embryogenesis and implantation as well as the post-implantation embryo development, but also the composition of the follicular fluid as a microenvironment of enormous importance for the maturation of the oocytes which thyroid autoantibodies reach via the blood-follicle barrier.

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.

Schilddrüse: Fertilität, Schwangerschaft und Laktation

Schilddrüsenhormone und Schilddrüsenerkrankungen spielen eine wichtige Rolle bei Fertilität, Schwangerschaft und Laktation. Die diversen Richtlinien und Expertenempfehlungen zur Diagnostik und Therapie von Schilddrüsenerkrankungen bei Kinderwunsch und Schwangerschaft sind teils heterogen und oftmals ohne klare Handlungsanweisung für oder gegen eine bestimmte Maßnahme, was eine gewisse Verunsicherung hervorruft. In diesem Übersichtsartikel möchten wir daher die derzeitige Evidenz auf diesem Gebiet in Bezug auf praktische Handlungsanweisungen darlegen, um dem Leser für die Praxis eine nützliche Entscheidungshilfe an die Hand zu geben. Wir werden besonders auf die aktuelle Evidenzlage bzgl. der Behandlung der latenten Hypothyreose präkonzeptionell, bei Infertilität und in der Schwangerschaft eingehen, sowie auf die Wichtigkeit der Beratung und gemeinsamen Therapieentscheidung bei Hyperthyreose und Kinderwunsch bzw. Schwangerschaft. Wir möchten auch besonders betonen, dass diverse wichtige Studien erst nach Publikation der aktuellen Richtlinien auf diesem Gebiet veröffentlicht wurden, was in der Routinebehandlung unserer Patientinnen natürlich berücksichtigt werden sollte. Da manifeste Schilddrüsenerkrankungen präkonzeptionell und in der Schwangerschaft häufig und in der Regel therapiebedürftig sind, plädieren wir für ein generelles Screening auf Schilddrüsenfunktionsstörungen bei allen Frauen mit Kinderwunsch sowie bei allen mit positivem Schwangerschaftstest.

Insufficient maternal iodine intake is associated with subfecundity, reduced foetal growth, and adverse pregnancy outcomes in the Norwegian Mother, Father and Child Cohort Study

BACKGROUND

Severe iodine deficiency impacts fertility and reproductive outcomes. The potential effects of mild-to-moderate iodine deficiency are not well known. The aim of this study was to examine whether iodine intake was associated with subfecundity (i.e. > 12 months trying to get pregnant), foetal growth, and adverse pregnancy outcomes in a mild-to-moderately iodine-deficient population.

METHODS

We used the Norwegian Mother, Father and Child Cohort Study (MoBa) and included 78,318 pregnancies with data on iodine intake and pregnancy outcomes. Iodine intake was calculated using an extensive food frequency questionnaire in mid-pregnancy. In addition, urinary iodine concentration was available in a subsample of 2795 pregnancies. Associations were modelled continuously by multivariable regression controlling for a range of confounding factors.

RESULTS

The median iodine intake from food was 121 μg/day and the median urinary iodine was 69 μg/L, confirming mild-to-moderate iodine deficiency. In non-users of iodine supplements (n = 49,187), low iodine intake (< 100-150 μg/day) was associated with increased risk of preeclampsia (aOR = 1.14 (95% CI 1.08, 1.22) at 75 vs. 100 μg/day, p overall < 0.001), preterm delivery before gestational week 37 (aOR = 1.10 (1.04, 1.16) at 75 vs. 100 μg/day, p overall = 0.003), and reduced foetal growth (- 0.08 SD (- 0.10, - 0.06) difference in birth weight z-score at 75 vs. 150 μg/day, p overall < 0.001), but not with early preterm delivery or intrauterine death. In planned pregnancies (n = 56,416), having an iodine intake lower than ~ 100 μg/day was associated with increased prevalence of subfecundity (aOR = 1.05 (1.01, 1.09) at 75 μg/day vs. 100 μg/day, p overall = 0.005). Long-term iodine supplement use (initiated before pregnancy) was associated with increased foetal growth (+ 0.05 SD (0.03, 0.07) on birth weight z-score, p < 0.001) and reduced risk of preeclampsia (aOR 0.85 (0.74, 0.98), p = 0.022), but not with the other adverse pregnancy outcomes. Urinary iodine concentration was not associated with any of the dichotomous outcomes, but positively associated with foetal growth (n = 2795, p overall = 0.017).

CONCLUSIONS

This study shows that a low iodine intake was associated with restricted foetal growth and a higher prevalence of preeclampsia in these mild-to-moderately iodine-deficient women. Results also indicated increased risk of subfecundity and preterm delivery. Initiating iodine supplement use in pregnancy may be too late.

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.