What is a varicocele and how does it affect male fertility?

A varicocele is an abnormal dilation of the pampiniform plexus which is the network of veins responsible for draining blood from the testicles. It is a common condition and is recognised as one of the most frequent potentially correctable causes of male infertility (Lundy et al., 2017).

Varicoceles affect fertility by disrupting the normal testicular environment required for effective sperm production. The impaired blood flow can lead to increased scrotal temperature, reduced oxygen supply, and elevated oxidative stress. These changes negatively impact testicular function, resulting in reduced sperm concentration, impaired motility, and abnormal morphology.

Recent evidence further supports the clinical significance of varicoceles in male infertility. A systematic review and meta-analysis found that treatment of varicoceles in infertile men is associated with improved pregnancy rates and increased sperm concentration, particularly in those with abnormal semen parameters. However, improvements in sperm motility and morphology are less consistent (Fallara et al., 2022).

In summary, a varicocele can impair male fertility by creating a suboptimal environment for spermatogenesis, leading to poorer semen quality. Importantly, in selected patients, especially those with abnormal semen analysis, treatment may improve fertility outcomes and increase the likelihood of achieving pregnancy.

Lundy SD, Sabanegh ES Jr. Varicocele management for infertility and pain: A systematic review. Arab J Urol. 2017 Dec 14;16(1):157-170. doi: 10.1016/j.aju.2017.11.003. PMID: 29713547; PMCID: PMC5922006.

Fallara G, Capogrosso P, Pozzi E, Belladelli F, Corsini C, Boeri L, Candela L, Schifano N, Dehò F, Castiglione F, Muneer A, Montorsi F, Salonia A. The Effect of Varicocele Treatment on Fertility in Adults: A Systematic Review and Meta-analysis of Published Prospective Trials. Eur Urol Focus. 2023 Jan;9(1):154-161. doi: 10.1016/j.euf.2022.08.014. Epub 2022 Sep 20. PMID: 36151030.

When is surgical intervention recommended for varicocele?

Surgical intervention for varicocele is recommended in carefully selected patients where there is clear clinical relevance to fertility or symptoms. Current evidence supports treatment primarily in men with a clinically palpable varicocele, abnormal semen parameters, and infertility where no other significant cause has been identified.

In these cases, surgery is considered a targeted intervention aimed at improving testicular function and reproductive outcomes. Conversely, surgery is generally not recommended in men with normal semen parameters or subclinical (non-palpable) varicoceles, as the likelihood of benefit is low (Leslie et al., 2023).

Indications may also extend to adolescents with testicular asymmetry or men experiencing persistent scrotal pain attributable to the varicocele. However, the decision to intervene should always be individualised, taking into account fertility goals, duration of infertility, and partner factors. Overall, surgery is best viewed as a selective, evidence-based intervention rather than a routine treatment for all varicoceles.

Leslie SW, Sajjad H, Siref LE. Varicocele. [Updated 2023 Nov 13]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2026 Jan-. Available from: https://www.ncbi.nlm.nih.gov/sites/books/NBK448113/

Which patients benefit most from varicocele repair?

The patients who derive the greatest benefit from varicocele repair are those with demonstrable impairment in semen quality and a clinically significant varicocele (Fallara et al., 2023).

Evidence from a systematic review and meta-analysis by Fallara and colleagues highlights that improvements in outcomes are most pronounced in men with abnormal baseline semen analysis, reinforcing the importance of appropriate patient selection.

Men with otherwise unexplained infertility, relatively preserved testicular function, and partners without major fertility issues tend to have the most favourable outcomes. In contrast, those with normal semen parameters or advanced, multifactorial infertility are less likely to experience meaningful improvement.

This highlights a key clinical principle: varicocele repair is most effective when there is a clear, correctable male factor contributing to infertility, rather than as a general or preventative measure.

Fallara G, Capogrosso P, Pozzi E, Belladelli F, Corsini C, Boeri L, Candela L, Schifano N, Dehò F, Castiglione F, Muneer A, Montorsi F, Salonia A. The Effect of Varicocele Treatment on Fertility in Adults: A Systematic Review and Meta-analysis of Published Prospective Trials. Eur Urol Focus. 2023 Jan;9(1):154-161. doi: 10.1016/j.euf.2022.08.014. Epub 2022 Sep 20. PMID: 36151030.

How does surgery impact sperm parameters and fertility outcomes?

Varicocele repair has been shown to have a positive impact on sperm parameters and, in selected patients, fertility outcomes, although the degree of improvement can vary. Evidence from recent literature, including the study by Toprak and colleagues, supports the role of varicocelectomy in improving testicular function, particularly in men with clinically significant varicoceles and abnormal semen parameters.

Surgically correcting a varicocele helps restore a more optimal testicular environment by reducing scrotal temperature, improving blood flow, and decreasing oxidative stress. These changes can enhance spermatogenesis, leading to measurable improvements in semen quality. Studies consistently report increases in sperm concentration following surgery, reflecting improved sperm production. Improvements in motility and morphology are also observed, although these tend to be more variable and may not occur in all patients (Toprak et al., 2024).

Importantly, the literature indicates that varicocele repair is associated with improved reproductive outcomes, including higher rates of natural conception and improved outcomes in assisted reproductive techniques. However, these benefits are most evident in appropriately selected patients, particularly those with abnormal baseline semen parameters and no significant female factor infertility.

Clinically, while varicocele repair may not normalise all semen parameters, it can significantly enhance overall fertility potential. Improvements are typically seen within 3 to 6 months following surgery, corresponding to the duration of the spermatogenic cycle, although continued improvement may occur over a longer period in some cases (Toprak et al., 2024).

In summary, varicocele surgery can lead to meaningful improvements in both sperm quality and fertility outcomes, particularly when performed in the right clinical context, reinforcing its role as a key, potentially corrective intervention in male infertility.

Toprak T, Harraz A, Saleh R, Shah R, Agarwal A. Impact of varicocele repair on semen parameters and spontaneous pregnancy: An endless debate put to rest. Arab J Urol. 2024 Jun 13;22(4):191-194. doi: 10.1080/20905998.2024.2367341. PMID: 39355792; PMCID: PMC11441012.

What are the risks and success rates associated with varicocele surgery?

Varicocele surgery is generally considered safe and effective, particularly when performed using microsurgical techniques. Reported outcomes indicate that approximately 70% of patients experience improvement in semen parameters, and 40–60% of couples achieve improved conception rates following repair (Leslie et al., 2023).

However, success is not universal, and patients should be counselled that surgery improves the probability of fertility rather than guaranteeing pregnancy. Outcomes depend heavily on baseline fertility status, female partner factors, and the severity of the varicocele (Leslie et al., 2023).

Potential risks are relatively uncommon but include hydrocele formation, recurrence or persistence of the varicocele, infection, and, rarely, damage to surrounding structures such as the testicular artery (Leslie et al., 2023).

In summary, varicocele repair is a low-risk intervention with moderate success rates, offering the greatest benefit in well-selected patients with abnormal semen parameters and otherwise unexplained infertility.

Leslie SW, Sajjad H, Siref LE. Varicocele. [Updated 2023 Nov 13]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2026 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK448113/