Protocol for developing a core outcome set for male infertility research: an international consensus development study

Assessing the uptake of infertility core outcome set in IVF randomized controlled trials

STUDY QUESTION

Do the infertility core outcome set and standardized definitions affect the outcome selection for randomized controlled trials, and what aspects should be further improved in the future?

SUMMARY ANSWER

Intrauterine pregnancy demonstrated the highest uptake level, whereas others were low, especially in neonatal outcomes; as time progresses, the target sample size increases, and with prospective registration, the consistency between outcomes reported in registrations and infertility core outcome set improves significantly.

WHAT IS KNOWN ALREADY

The infertility core outcome set, published on 30 November 2020, aims to standardize outcome reporting and prevent selective reporting bias; however, there is a paucity of research evaluating its actual adoption, which is crucial for the timely promotion of transparency, standardization, adjustment of development strategies, and efficient resource utilization.

STUDY DESIGN, SIZE, DURATION

This cross-sectional study included 1673 eligible randomized controlled trial registrations for infertility in 18 registries from March 2004 to July 2024 based on registry entries.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 4625 infertility-related studies from 1 November 1999 to 26 July 2024 were retrieved in the World Health Organization International Clinical Trials Registry Platform. Finally, 1673 randomized controlled trial registrations were selected and divided into four period groups. Period, target sample size, prospective registration, blinding, support, and countries/regions were potential influencing factors. The consistency of outcomes, definitions, and standardized denominators of randomized controlled trial registry entries with the recommendations of the infertility core outcome set were the main outcomes. Independent retrieval, screening, data extraction, and consistency evaluations by two assessors and expert consultations were conducted to assess the uptake and potential influencing factors of the infertility core outcome set in randomized controlled trials involving infertile patients undergoing in vitro fertilization.

MAIN RESULTS AND THE ROLE OF CHANCE

Results reveal that the reporting level in the pregnancy domain was significantly higher than that in the neonatal domain (13.6% vs 5.7%). Intrauterine pregnancy (66.9%), live birth (27.6%), and miscarriage (26.5%) had relatively high uptake levels. The uptake of most core outcomes and domains, as well as the total number of reported core outcomes, showed statistically significant differences based on period, target sample size, and prospective registration. Multivariable analyses supported the above finding. Reasons responsible for the results may be attributed to the lack of effective promotional measures, as well as the limited researcher awareness regarding this core outcome set.

LIMITATIONS, REASONS FOR CAUTION

Some results in this study may have been influenced by the subjective judgment of the evaluators due to the complexity of the information in registries.

WIDER IMPLICATIONS OF THE FINDINGS

Uptake of most core outcomes or domains is increasing but is not yet ideal. Moreover, the upward trend cannot be solely attributed to the publication of the infertility core outcome set. The key to promoting uptake is to thoroughly explore and recognize the factors that both facilitate and hinder the uptake of the infertility core outcome set, further expand and publicize the core outcome set, and foster multidisciplinary or multiple stakeholder cooperation.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by the Capital's Funds for Health Improvement and Research (CFH 2024-2G-4097), as well as the special fund of Beijing Key Clinical Specialty Construction Project. The authors have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

http://www.comet-initiative.org/Studies/Details/3184.

A Mendelian randomization study on causal relationship between metabolic factors and abnormal spermatozoa

Background

Male infertility is a global health problem. There is an increasing attention on the association of metabolic status with spermatogenesis. However, the impacts of metabolic factors on semen parameters are still unclear. To provide evidence for developing appropriate interventions on disease screening and prevention, we performed a Mendelian randomization (MR) analysis to assess causality between various metabolic factors and abnormal spermatozoa.

Methods

We conducted a two-sample MR study to appraise the causal effects of 16 metabolic factors (including indexes of metabolic traits, glucose metabolism, lipid profile, adipokines, uric acid and metabolic diseases) on abnormal spermatozoa from genome-wide association studies (GWASs). Filtering with strict criteria, eligible genetic instruments closely associated with each of the factors were extracted. We employed inverse variance weighted for major analysis, with supplement MR methods including MR-Egger and weighted median. Heterogeneity and pleiotropy tests were further used to detect the reliability of analysis.

Results

After rigorous quality control in this MR framework, we identified that body fat percentage [odds ratio (OR) =1.49, 95% confidence interval (CI): 1.01-2.20, P=0.046] and resistin (OR =1.55, 95% CI: 1.11-2.19, P=0.01) were causally associated with a higher risk of abnormal spermatozoa. In terms of other indexes of metabolic traits, glucose metabolism, serum lipid profile and uric acid and metabolic diseases including type 2 diabetes mellitus (T2DM) and non-alcoholic fatty liver disease (NAFLD), no causal effects were observed (P>0.05).

Conclusions

Our MR analysis provides robust evidence that body fat percentage and resistin are risk factors for abnormal spermatozoa, suggesting implications of identifying them for potential interventions and clinical therapies in male infertility. Further investigation in larger-scale GWASs on subgroups of abnormal spermatozoa will verify impacts of metabolic factors on spermatogenesis.

The effects of radiofrequency exposure on male fertility: A systematic review of human observational studies with dose-response meta-analysis

BACKGROUND

The World Health Organization (WHO) is bringing together evidence on radiofrequency electromagnetic field (RF-EMF) exposure in relation to health outcomes, previously identified as priorities for research and evaluation by experts in the field, to inform exposure guidelines. A suite of systematic reviews have been undertaken by a network of topic experts and methodologists to collect, assess and synthesise data relevant to these guidelines. Following the WHO handbook for guideline development and the COSTER conduct guidelines, we systematically reviewed the evidence on the potential effects of RF-EMF exposure on male fertility in human observational studies.

METHODS

We conducted a broad and sensitive search for potentially relevant records within the following bibliographic databases: MEDLINE; Embase; Web of Science and EMF Portal. We also conducted searches of grey literature through relevant databases including OpenGrey, and organisational websites and consulted RF-EMF experts. We hand searched reference lists of included study records and for citations of these studies. We included quantitative human observational studies on the effect of RF-EMF exposure in adult male participants on infertility: sperm concentration; sperm morphology; sperm total motility; sperm progressive motility; total sperm count; and time to pregnancy. Titles and abstracts followed by full texts were screened in blinded duplicate against pre-set eligibility criteria with consensus input from a third reviewer as required. Data extraction from included studies was completed by two reviewers, as was risk of bias assessment using the Office of Health Assessment and Translation (OHAT) tool. We conducted a dose-response meta-analysis as possible and appropriate. Certainty of the evidence was assessed by two reviewers using the OHAT GRADE tool with input from a third reviewer as required.

RESULTS

We identified nine studies in this review; seven were general public studies (with the general public as the population of interest) and two were occupational studies (with specific workers/workforces as the population of interest). General public studies. Duration of phone use: The evidence is very uncertain surrounding the effects of RF-EMF on sperm concentration (10/6 mL) (MD (mean difference) per hour of daily phone use 1.6 106/mL, 95 % CI -1.7 to 4.9; 3 studies), sperm morphology (MD 0.15 percentage points of deviation of normal forms per hour, 95 % CI -0.21 to 0.51; 3 studies), sperm progressive motility (MD -0.46 percentage points per hour, 95 % CI -1.04 to 0.13; 2 studies) and total sperm count (MD per hour -0.44 106/ejaculate, 95 % CI -2.59 to 1.7; 2 studies) due to very low-certainty evidence. Four additional studies reported on the effect of mobile phone use on sperm motility but were unsuitable for pooling; only one of these studies identified a statistically significant effect. All four studies were at risk of exposure characterisation and selection bias; two of confounding, selective reporting and attrition bias; three of outcome assessment bias and one used an inappropriate statistical method. Position of phone: There may be no or little effect of carrying a mobile phone in the front pocket on sperm concentration, total count, morphology, progressive motility or on time to pregnancy. Of three studies reporting on the effect of mobile phone location on sperm total motility and, or, total motile count, one showed a statistically significant effect. All three studies were at risk of exposure characterisation and selection bias; two of confounding, selective reporting and attrition bias; three of outcome assessment bias and one used inappropriate statistical method. RF-EMF Source: One study indicates there may be little or no effect of computer or other electric device use on sperm concentration, total motility or total count. This study is at probably high risk of exposure characterisation bias and outcome assessment bias. Occupational studies. With only two studies of occupational exposure to RF-EMF and heterogeneity in the population and exposure source (technicians exposed to microwaves or seamen exposed to radar equipment), it was not plausible to statistically pool findings. One study was at probably or definitely high risk of bias across all domains, the other across domains for exposure characterisation bias, outcome assessment bias and confounding.

DISCUSSION

The majority of evidence identified was assessing localised RF-EMF exposure from mobile phone use on male fertility with few studies assessing the impact of phone position. Overall, the evidence identified is very uncertain about the effect of RF-EMF exposure from mobile phones on sperm outcomes. One study assessed the impact of other RF-EMF sources on male fertility amongst the general public and two studies assessed the impact of RF-EMF exposure in occupational cohorts from different sources (radar or microwave) on male fertility. Further prospective studies conducted with greater rigour (in particular, improved accuracy of exposure measurement and appropriate statistical method use) would build the existing evidence base and are required to have greater certainty in any potential effects of RF-EMF on male reproductive outcomes. Prospero Registration: CRD42021265401 (SR3A).

Pharmacological non-hormonal treatment options for male infertility: a systematic review and network meta-analysis

BACKGROUND

Male factor infertility affect up to 50% of couples unable to conceive spontaneously. Several non-hormonal pharmacological treatments have been proposed to boost spermatogenesis and increase chances of conception in men with infertility. Still, no clear evidence exists on the most effective treatment strategy.

OBJECTIVE

We aimed to compare the effectiveness of non-hormonal pharmacological treatment options for men with infertility using a systematic review and network meta-analysis.

METHODS

We searched MEDLINE, EMBASE, and CENTRAL until October 2023 for randomised/quasi-randomised trials that evaluated any non-hormonal pharmacological treatment options for men with idiopathic semen abnormalities or those with hypogonadism. We performed pairwise and network meta-analyses using a random effect model. We assessed risk of bias, heterogeneity, and network inconsistency. We calculated the mean rank and the surface under the cumulative ranking curve (SUCRA) for each intervention the maximum likelihood to achieve each of reported outcomes. We reported primarily on sperm concentration and other important semen and biochemical outcomes using standardised mean difference (SMD) and 95% confidence-intervals(CI).

RESULTS

We included 14 randomised trials evaluating four treatments (Clomiphene citrate, Tamoxifen, Aromatase inhibitors, anti-oxidants) and their combinations in 1342 men. The overall quality of included trials was low. Sperm concentration improved with clomiphene compared to anti-oxidants (SMD 2.15, 95%CI 0.78-3.52), aromatase inhibitor (SMD 2.93, 95%CI 1.23-4.62), tamoxifen (SMD - 1.96, 95%CI -3.57; -0.36) but not compared to placebo (SMD - 1.53, 95%CI -3.52- 0.47). Clomiphene had the highest likelihood to achieve the maximum change in sperm concentration (SUCRA 97.4). All treatments showed similar effect for sperm motility, semen volume, and normal sperm morphology. FSH levels showed significant improvement with clomiphene vs.anti-oxidant (SMD 1.48, 95%CI 0.44-2.51) but not compared to placebo. The evidence networks for LH and testosterone suffered from significant inconsistency (p = 0.01) with similar trend of improvement with clomiphene compared to other treatments but not compared to placebo.

CONCLUSION

There is insufficient evidence to support the routine use of Clomiphene, tamoxifen, and aromatase inhibitors to optimise semen parameters in men with infertility. Future randomised trials are needed to confirm the efficacy of clomiphene in improving fertility outcomes in men.

PROSPERO

CRD42023430179.

Cyto- and Histopographic Assessment of CPA3-Positive Testicular Mast Cells in Obstructive and Non-Obstructive Azoospermia

Infertility is an important personal and society disease, of which the male factor represents half of all causes. One of the aspects less studied in male infertility is the immunological testicular microenvironment. Mast cells (MCs), having high potential for regulating spermatogenesis due to fine-tuning the state of the integrative buffer metabolic environment, are one of the most crucial cellular subpopulations of the testicular interstitium. One important component of the MC secretome is proteases that can act as proinflammatory agents and in extracellular matrix (ECM) remodeling. In the testis, MCs are an important cell component of the testicular interstitial tissue (TIT). However, there are still no studies addressing the analysis of a specific MC protease-carboxypeptidase A3 (CPA3)-in cases with altered spermatogenesis. The cytological and histotopographic features of testicular CPA3+ MCs were examined in a study involving 34 men with azoospermia. As revealed, in cases with non-obstructive azoospermia, a higher content of CPA3+ MCs in the TIT and migration to the microvasculature and peritubular tissue of seminiferous tubules were observed when compared with cases with obstructive azoospermia. Additionally, a high frequency of CPA3+ MCs colocalization with fibroblasts, Leydig cells, and elastic fibers was detected in cases with NOA. Thus, CPA3 seems to be of crucial pathogenetic significance in the formation of a profibrogenic background of the tissue microenvironment, which may have direct and indirect effects on spermatogenesis.

A 20-year overview of fertility preservation in boys: new insights gained through a comprehensive international survey

STUDY QUESTION

Twenty years after the inception of the first fertility preservation programme for pre-pubertal boys, what are the current international practices with regard to cryopreservation of immature testicular tissue?

SUMMARY ANSWER

Worldwide, testicular tissue has been cryopreserved from over 3000 boys under the age of 18 years for a variety of malignant and non-malignant indications; there is variability in practices related to eligibility, clinical assessment, storage, and funding.

WHAT IS KNOWN ALREADY

For male patients receiving gonadotoxic treatment prior to puberty, testicular tissue cryopreservation may provide a method of fertility preservation. While this technique remains experimental, an increasing number of centres worldwide are cryopreserving immature testicular tissue and are approaching clinical application of methods to use this stored tissue to restore fertility. As such, standards for quality assurance and clinical care in preserving immature testicular tissue should be established.

STUDY DESIGN SIZE DURATION

A detailed survey was sent to 17 centres within the recently established ORCHID-NET consortium, which offer testicular tissue cryopreservation to patients under the age of 18 years. The study encompassed 60 questions and remained open from 1 July to 1 November 2022.

PARTICIPANTS/MATERIALS SETTING METHODS

Of the 17 invited centres, 16 completed the survey, with representation from Europe, Australia, and the USA. Collectively, these centres have cryopreserved testicular tissue from patients under the age of 18 years. Data are presented using descriptive analysis.

MAIN RESULTS AND THE ROLE OF CHANCE

Since the establishment of the first formal fertility preservation programme for pre-pubertal males in 2002, these 16 centres have cryopreserved tissue from 3118 patients under the age of 18 years, with both malignant (60.4%) and non-malignant (39.6%) diagnoses. All centres perform unilateral biopsies, while 6/16 sometimes perform bilateral biopsies. When cryopreserving tissue, 9/16 centres preserve fragments sized ≤5 mm3 with the remainder preserving fragments sized 6-20 mm3. Dimethylsulphoxide is commonly used as a cryoprotectant, with medium supplements varying across centres. There are variations in funding source, storage duration, and follow-up practice. Research, with consent, is conducted on stored tissue in 13/16 centres.

LIMITATIONS REASONS FOR CAUTION

While this is a multi-national study, it will not encompass every centre worldwide that is cryopreserving testicular tissue from males under 18 years of age. As such, it is likely that the actual number of patients is even higher than we report. Whilst the study is likely to reflect global practice overall, it will not provide a complete picture of practices in every centre.

WIDER IMPLICATIONS OF THE FINDINGS

Given the research advances, it is reasonable to suggest that cryopreserved immature testicular tissue will in the future be used clinically to restore fertility. The growing number of patients undergoing this procedure necessitates collaboration between centres to better harmonize clinical and research protocols evaluating tissue function and clinical outcomes in these patients.

STUDY FUNDING/COMPETING INTERESTS

K.D. is supported by a CRUK grant (C157/A25193). R.T.M. is supported by an UK Research and Innovation (UKRI) Future Leaders Fellowship (MR/S017151/1). The MRC Centre for Reproductive Health at the University of Edinburgh is supported by MRC (MR/N022556/1). C.L.M. is funded by Kika86 and ZonMW TAS 116003002. A.M.M.v.P. is supported by ZonMW TAS 116003002. E.G. was supported by the Research Program of the Research Foundation-Flanders (G.0109.18N), Kom op tegen Kanker, the Strategic Research Program (VUB_SRP89), and the Scientific Fund Willy Gepts. J.-B.S. is supported by the Swedish Childhood Cancer Foundation (TJ2020-0026). The work of NORDFERTIL is supported by the Swedish Childhood Cancer Foundation (PR2019-0123; PR2022-0115), the Swedish Research Council (2018-03094; 2021-02107), and the Birgitta and Carl-Axel Rydbeck's Research Grant for Paediatric Research (2020-00348; 2021-00073; 2022-00317; 2023-00353). C.E is supported by the Health Department of the Basque Government (Grants 2019111068 and 2022111067) and Inocente Inocente Foundation (FII22/001). M.P.R. is funded by a Medical Research Council Centre for Reproductive Health Grant No: MR/N022556/1. A.F. and N.R. received support from a French national research grant PHRC No. 2008/071/HP obtained by the French Institute of Cancer and the French Healthcare Organization. K.E.O. is funded by the University of Pittsburgh Medical Center and the US National Institutes of Health HD100197. V.B-L is supported by the French National Institute of Cancer (Grant Seq21-026). Y.J. is supported by the Royal Children's Hospital Foundation and a Medical Research Future Fund MRFAR000308. E.G., N.N., S.S., C.L.M., A.M.M.v.P., C.E., R.T.M., K.D., M.P.R. are members of COST Action CA20119 (ANDRONET) supported by COST (European Cooperation in Science and Technology). The Danish Child Cancer Foundation is also thanked for financial support (C.Y.A.). The authors declare no competing interests.

TRIAL REGISTRATION NUMBER

N/A.

Developing Consensus on Clinical Outcomes for Children with Mild Pneumonia: A Delphi Study

BACKGROUND

The absence of consensus for outcomes in pediatric antibiotic trials is a major barrier to research harmonization and clinical translation. We sought to develop expert consensus on study outcomes for clinical trials of children with mild community-acquired pneumonia (CAP).

METHODS

Applying the Delphi method, a multispecialty expert panel ranked the importance of various components of clinical response and treatment failure outcomes in children with mild CAP for use in research. During Round 1, panelists suggested additional outcomes in open-ended responses that were added to subsequent rounds of consensus building. For Rounds 2 and 3, panelists were provided their own prior responses and summary statistics for each item in the previous round. The consensus was defined by >70% agreement.

RESULTS

The expert panel determined that response to and failure of treatment should be addressed at a median of 3 days after initiation. Complete or substantial improvement in fever, work of breathing, dyspnea, tachypnea when afebrile, oral intake, and activity should be included as components of adequate clinical response outcomes. Clinical signs and symptoms including persistent or worsening fever, work of breathing, and reduced oral intake should be included in treatment failure outcomes. Interventions including receipt of parenteral fluids, supplemental oxygen, need for high-flow nasal cannula oxygen therapy, and change in prescription of antibiotics should also be considered in treatment failure outcomes.

CONCLUSIONS

Clinical response and treatment failure outcomes determined by the consensus of this multidisciplinary expert panel can be used for pediatric CAP studies to provide objective data translatable to clinical practice.