Paternal Subclinical Hypothyroidism Affects the Clinical Outcomes of In Vitro Fertilization/Intracytoplasmic Sperm Injection

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.

Thyroid disorders and male sexual dysfunction

Though early research suggested that thyroid hormones were not involved with the testes, male spermatogenesis, or erectile function, investigations on this topic over the past few decades have increased and shed new light. A literature review of studies conducted between 1963 and 2022 regarding male sexual dysfunction (SD) and thyroid disorders was performed to define the diagnostic consideration, pathophysiology, and management of SD secondary to thyroid dysregulation. This article provides evidence and interpretation of prior clinical and preclinical studies and contextualizes these studies for clinical practice. Clinical manifestations of SDs included erectile and ejaculatory dysfunction, impaired spermatogenesis, and disruption of the hypothalamic-pituitary-gonadal axis. Our aim of this communication was to perform a literature review detailing the impact of thyroid disorders on male SD. We hope to provide a framework for practicing urologists, endocrinologists, or general practitioners when evaluating patients with concurrent thyroid and male SD. It is important to recognize that thyroid disorders can be an important part of the pathophysiology of male SD in patients. Future research studies are needed to further elucidate the mechanisms involved.

Thyroid Autoimmunity Is Not Associated with Embryo Quality or Pregnancy Outcomes in Euthyroid Women Undergoing Assisted Reproductive Technology in China

Background: Studies have shown that thyroid autoimmunity (TAI) is associated with increased risks of adverse pregnancy outcomes. The aim of this study was to investigate the associations between TAI and embryo quality in euthyroid women undergoing in vitro fertilization or intracytoplasmic sperm injection (IVF/ICSI). Methods: This retrospective cohort study included euthyroid infertile women with and without TAI (defined as a serum thyroperoxidase concentration ≥34 IU/mL or a thyroglobulin concentration ≥115.0 IU/mL) who underwent their first complete IVF/ICSI treatment cycles at a tertiary referral center between April 2016 and February 2022. Embryo quality measurements and clinical outcomes were compared between women with (TAI positive) and without TAI (TAI negative). The high-quality cleavage embryo rate and cumulative live birth rate (cLBR) were the primary outcomes. Results: A total of 499 TAI-positive and 2945 TAI-negative women were included in this study, and their mean (standard deviation) ages were 31.6 (4.5) and 30.9 (4.4) years, respectively (p = 0.001). The overall analysis showed no significant differences between TAI-negative and TAI-positive women in the high-quality cleavage embryo rate (n/N: 11,139/22,553 vs. 1971/3820; adjusted rate: 52.8% vs. 53.4%, p = 0.66) and cLBR (1917/2945 vs. 327/499; 53.4% vs. 56.2%, p = 0.31). Moreover, no significant differences were observed between TAI-negative and TAI-positive women in the rates of oocyte retrieval (35,078/51,978 vs. 5853/8628; 69.1% vs. 69.4%; p = 0.65), fertilization (23,067/34,197 vs. 3902/5728; 61.1% vs. 62.2%, p = 0.34), embryo utilization (18,233/22,553 vs. 3156/3820; 80.2% vs. 80.8%, p = 0.61), blastocyst formation (7051/13,721 vs. 1192/2330; 48.5% vs. 48.4%, p = 0.97), and high-quality blastocysts (4819/13,721 vs. 799/2330; 29.9% vs. 29.4%, p = 0.73). Furthermore, no significant differences were observed between TAI-negative and TAI-positive women in the clinical pregnancy rate (1524/2808 vs. 248/482; 46.7% vs. 44.6%, p = 0.40), early pregnancy loss rate (156/1524 vs. 23/248; 13.5% vs. 11.5%, p = 0.44), and LBR (1338/2808 vs. 218/482; 37.4% vs. 36.0%, p = 0.55) of the first transfer cycle. Conclusions: This study demonstrated that TAI in women was not associated with embryo quality or the cLBR following IVF/ICSI. Future large studies are warranted to confirm these findings.

Subclinical Hypothyroidism and Sperm DNA Fragmentation: A Cross-sectional Study of 5401 Men Seeking Infertility Care

CONTEXT

Our previous study showed that paternal subclinical hypothyroidism (SCH) had a detrimental effect on the clinical outcomes of assisted reproductive technologies. However, it remains to be determined whether paternal SCH affects sperm DNA integrity.

OBJECTIVE

To investigate the association between SCH and sperm DNA fragmentation in men seeking infertility care.

METHODS

This cross-sectional study included 4983 men with euthyroidism and 418 men with SCH seeking infertility treatment in a tertiary care academic medical center between January 2017 and December 2021. The outcome measures were the absolute DNA fragmentation index (DFI) and the risk of abnormal DFI (defined as DFI ≥ 25% or ≥ 30%).

RESULTS

The mean (SD) age of men with euthyroidism and men with SCH was 34.20 (5.97) and 35.35 (6.48) years, respectively (P < 0.001). The difference in DFI was not statistically significant (adjusted mean: 19.7% vs 18.9% in the SCH and euthyroidism groups, respectively; P = 0.07) after confounder adjustment. A DFI ≥25% was significantly more frequent in men with SCH (20.57%) than in men with euthyroidism (14.49%) after confounder adjustment [odds ratio (OR) 1.43 (95% CI 1.09-1.88)]. DFI ≥ 30% was also significantly more common in men with SCH (11.72%) than in men with euthyroidism [6.74%; OR 1.84 (95% CI 1.34-2.52)]. In addition, thyroid-stimulating hormone concentration was significantly associated with an increased risk of having a DFI ≥25% (P < 0.001) or ≥30% (P = 0.011).

CONCLUSION

SCH was significantly associated with an increased risk of an abnormal DFI.

Normal-Range Paternal Serum-Free Thyroxine Concentrations and Outcomes of Assisted Reproductive Technologies

Background: A recent study showed that paternal subclinical hypothyroidism adversely affects the clinical outcomes of assisted reproductive technologies (ARTs). The aim of this study was to determine whether paternal serum-free thyroxine (fT4) concentrations within the reference range are associated with ART outcomes. Methods: This retrospective cohort study included 4066 couples who received 4894 ART treatment cycles in our clinic between April 1, 2016 and August 31, 2021. The differences in sperm parameters and ART outcomes across the paternal fT4 concentration tertiles were compared by using generalized linear models or generalized estimation equation models. The primary outcomes were clinical pregnancy rate (CPR) and live birth rate (LBR) per oocyte retrieval after the first embryo transfer cycle. Results: The mean ages of the males and their female partners were 32.8 (standard deviation, 5.0) and 30.7 (standard deviation, 4.1) years, respectively. No significant differences were observed in the sperm parameters or ART outcomes between the paternal fT4 concentration tertiles of the overall population. However, a stratified analysis of men aged ≥35 showed an adjusted CPR of 0.36 [confidence interval, CI: 0.27-0.45] for the lower paternal fT4 concentration tertile relative to the middle (adjusted rate: 0.45, CI: 0.38-0.53) and upper (adjusted rate: 0.43, CI: 0.36-0.51) tertiles (p for trend >0.05). The adjusted LBRs were 0.21 [CI: 0.15-0.30] for men aged ≥35 in the lower fT4 concentration tertile (p = 0.024, with reference to the upper tertile), 0.27 [CI: 0.21-0.35] for those in the middle tertile, and 0.30 [CI: 0.23-0.38] for those in the upper tertile. No differences in these outcomes were observed in men aged <35. The nonlinear smoothing curve obtained by using fT4 concentration as a continuous variable further supported these findings. Conclusions: Men of older reproductive age (≥35 years old) with low-normal fT4 concentrations within the reference range are associated with a decreased LBR. Future prospective studies are warranted to confirm the detrimental effects of low-normal paternal fT4 concentrations on ART outcomes.

Cumulative live birth rates after IVF/ICSI cycles with sperm prepared by density gradient centrifugation vs. swim-up: a retrospective study using a propensity score-matching analysis

BACKGROUND

Density gradient centrifugation (DGC) and swim-up (SU) are the two most widely used sperm preparation methods for in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI). However, existing comparisons of IVF/ICSI outcomes following these sperm preparation methods are insufficient and controversial.

METHODS

This retrospective study included all first autologous IVF and ICSI cycles performed between March 1, 2016, and December 31, 2020 in a single university-based center. A total of 3608 cycles were matched between DGC and SU using propensity score (PS) matching for potential confounding factors at a ratio of 1:1. The primary outcome was the cumulative live birth rate (cLBR) per aspiration.

RESULTS

PS matching provided 719 cycles after DGC and 719 cycles after SU. After adjusting for confounders, the recovery rate, progressive motility rate after sperm preparation, fertilization rate, good-quality embryo rate, and blastocyst formation rate were similar between the DGC and SU groups. The cLBR (odds ratio [OR] = 1.143, 95% confidence interval [CI]: 0.893-1.461) and LBR per transfer (OR = 1.082, 95% CI: 0.896-1.307) were also not significantly different between the groups. Furthermore, no significant differences were found in all of the laboratory and clinical outcomes following conventional IVF or ICSI cycles between the two groups. However, a significantly higher fertilization rate (β = 0.074, 95% CI: 0.008-0.140) was observed when using poor-quality sperm in the DGC group than in the SU group.

CONCLUSIONS

Sperm preparation using DGC and SU separately resulted in similar IVF/ICSI outcomes. Further studies are warranted to compare the effects of these methods on IVF/ICSI outcomes when using sperm from subgroups of different quality.

Thyroid disorders and pathospermia in the ART clinic patients

OBJECTIVE

Over the past decade, a decrease in the semen quality in men of reproductive age, along with an increase in the incidence of thyroid diseases among young patients have been clearly noticed. The study was designed to determine various forms of pathospermia in the ART clinic patients with thyroid disorders.

MATERIALS AND METHODS

168 men of reproductive age in infertile marriage were examined. Men with male infertility factor associated with erectile dysfunction and normospermia (9 patients, 5.3%) were excluded. The study included 159 men and the patients were divided into three groups: the 1^st study group consisted of men with non-obstructive azoospermia - 11 men (6.9%); the 2^nd study group included men with other forms of pathospermia - 38 men (23.9%) and the control group consisted of men in infertile marriage with normospermia - 110 men (69.2%). All patients had anthropometric measurements, laboratory tests, thyroid and testicular ultrasonography. Spermogram was analyzed in accordance with the WHO classification, 5^th revision, 2010.

RESULTS

Among all examined men with pathospermia (n = 49 patients), 51.02% had various thyroid disorders, while it was firstly verified in 34.7% men. In 45.5% patients with non-obstructive azoospermia, previously undiagnosed nodular goiter with normal values of thyroid-stimulating hormone and free thyroxine were found, and a significant correlation between nodular goiter and the presence of azoospermia was revealed: r = 0.610, p = .01.

CONCLUSION.

Men with various forms of pathospermia and patients of the ART clinic had higher risks of thyroid disorders than in general population that could possibly affect fertility. Patients of the ART clinic with non-obstructive azoospermia are at risk for nodular thyroid disorders, even with normal values of thyroid function tests, and require thyroid ultrasonography.