The Effect of Human Chorionic Gonadotropin Therapy on Semen Parameters and Pregnancy Rate after Varicocelectomy

Does Varicocele Repair Improve Conventional Semen Parameters? A Meta-Analytic Study of Before-After Data

PURPOSE

The purpose of this meta-analysis is to study the impact of varicocele repair in the largest cohort of infertile males with clinical varicocele by including all available studies, with no language restrictions, comparing intra-person conventional semen parameters before and after the repair of varicoceles.

MATERIALS AND METHODS

The meta-analysis was performed according to PRISMA-P and MOOSE guidelines. A systematic search was performed in Scopus, PubMed, Cochrane, and Embase databases. Eligible studies were selected according to the PICOS model (Population: infertile male patients with clinical varicocele; Intervention: varicocele repair; Comparison: intra-person before-after varicocele repair; Outcome: conventional semen parameters; Study type: randomized controlled trials [RCTs], observational and case-control studies).

RESULTS

Out of 1,632 screened abstracts, 351 articles (23 RCTs, 292 observational, and 36 case-control studies) were included in the quantitative analysis. The before-and-after analysis showed significant improvements in all semen parameters after varicocele repair (except sperm vitality); semen volume: standardized mean difference (SMD) 0.203, 95% CI: 0.129-0.278; p<0.001; I²=83.62%, Egger's p=0.3329; sperm concentration: SMD 1.590, 95% CI: 1.474-1.706; p<0.001; I²=97.86%, Egger's p<0.0001; total sperm count: SMD 1.824, 95% CI: 1.526-2.121; p<0.001; I²=97.88%, Egger's p=0.0063; total motile sperm count: SMD 1.643, 95% CI: 1.318-1.968; p<0.001; I²=98.65%, Egger's p=0.0003; progressive sperm motility: SMD 1.845, 95% CI: 1.537%-2.153%; p<0.001; I²=98.97%, Egger's p<0.0001; total sperm motility: SMD 1.613, 95% CI 1.467%-1.759%; p<0.001; l2=97.98%, Egger's p<0.001; sperm morphology: SMD 1.066, 95% CI 0.992%-1.211%; p<0.001; I²=97.87%, Egger's p=0.1864.

CONCLUSIONS

The current meta-analysis is the largest to date using paired analysis on varicocele patients. In the current meta-analysis, almost all conventional semen parameters improved significantly following varicocele repair in infertile patients with clinical varicocele.

Outcome reporting across randomized controlled trials evaluating potential treatments for male infertility: a systematic review

STUDY QUESTION

What are the primary outcomes and outcome measures used in randomized controlled trials (RCTs) evaluating potential treatments for male infertility in the last 10 years?

SUMMARY ANSWER

Outcome reporting across male infertility trials is heterogeneous with numerous definitions and measures used to define similar outcomes.

WHAT IS KNOWN ALREADY

No core outcome set for male infertility trials has been developed. Male infertility trials are unique in that they have potentially three participants, a man, a female partner and their offspring and this will likely lead to significant variation in outcome reporting in randomized trials.

STUDY DESIGN SIZE DURATION

A systematic review of RCTs mapping outcomes and outcome measures evaluating potential treatments for men with infertility registered in the Cochrane Register of Controlled Trials (CENTRAL) between January 2010 and July 2021.

PARTICIPANTS/MATERIALS SETTING METHODS

Abstract screening and study selection was undertaken in duplicate using a review protocol that was developed prior to commencing the review. No risk of bias assessment was undertaken as this review aims to report on outcome reporting only.

MAIN RESULTS AND THE ROLE OF CHANCE

One hundred and seventy-five RCTs were identified, and given the large number of studies we limited our review to the 100 largest trials. Seventy-nine different treatments were reported across the 100 largest RCTs including vitamin and dietary supplements (18 trials), surgical treatments (18 trials) and sperm selection techniques (22 trials). When considering the largest 100 trials (range: 80-2772 participants), 36 primary and 89 secondary outcomes were reported. Forty-seven trials reported a primary outcome and 36 trials clearly defined their primary outcome. Pregnancy outcomes were inconsistently reported and included pregnancy rate (51 trials), pregnancy loss including miscarriage, ectopic pregnancy, stillbirth (9 trials) and live birth (13 trials). Trials consistently reporting the same outcome frequently used different definitions. For example, semen quality was reported by 75 trials and was defined in 7 different ways, including; the World Health Organization (WHO) 2010 criteria (32 trials), WHO 1999 criteria (18 trials), WHO 1992 criteria (3 trials), WHO 1999 and 1992 criteria (1 trial) and the Kruger strict morphology criteria (1 trial).

LIMITATIONS REASONS FOR CAUTION

We only evaluated the 100 largest trials published in the last 10 years and did not report outcomes on the remaining 75. An outcome was included as a primary outcome only if clearly stated in the manuscript and we did not contact authors to clarify this. As our review mapped outcomes and outcome measures, we did not undertake an integrity assessment of the trials included in our review.

WIDER IMPLICATIONS OF THE FINDINGS

Most randomized trials evaluating treatments for male infertility report different outcomes. Only half of the RCTs reported pregnancy rate and even fewer reported live birth; furthermore, the definitions of these outcomes varies across trials. Developing, disseminating and implementing a minimum data set, known as a core outcome set, for male infertility research could help to improve outcome selection, collection and reporting.

STUDY FUNDING/COMPETING INTERESTS

A.P.-chairman of external scientific advisory committee of Cryos International Denmark ApS, member of the scientific advisory board for Cytoswim LDT and ExSeed Health. Guest lecture at the 'Insights for Fertility Conference', funded by MERK SERONO Limited. M.v.W.-holds a ZON-MW research grant. No external funding was obtained for this study.