The Effect of Subclinical Varicocele on Pregnancy Rates and Semen Parameters: a Systematic Review and Meta-Analysis

  • Taylor P. Kohn
  • Samuel J. Ohlander
  • Jake S. Jacob
  • Tina M. Griffin
  • Larry I. Lipshultz
  • Alexander W. Pastuszak
Andrology and Infertility (L Lipshultz, Section Editor)
Part of the following topical collections:
  1. Topical Collection on Andrology and Infertility


Purpose of Review

Current guidelines recommend against surgical repair of subclinical varicoceles (SCVs) for infertility; several studies demonstrate mixed fertility results after SCV correction. To determine whether surgical correction of SCV improves semen parameters and/or reproductive outcomes, we performed a systematic review and meta-analysis. Seven biomedical literature databases were searched through January 2018 for studies that assessed reproductive outcomes and/or change in semen parameters in men with corrected SCV compared to either (1) uncorrected SCV or (2) corrected clinical varicocele. Estimates were pooled using random-effects meta-analysis.

Recent Findings

Data were extracted from 13 studies involving 1357 men. Overall, the risk of bias for included studies was high and without a consistent SCV definition across studies. Surgical correction of SCV was associated with a minor increase in sperm density and total motile sperm count (TMSC) compared to uncorrected SCV. This increase in semen parameters is not clinically significant, as men prior to varicocelectomy were on average normospermic nor was correction of a SCV associated with an increase in pregnancy rates when compared to men with uncorrected SCV. Comparing corrected SCV to corrected clinical varicocele, SCV correction resulted in a smaller increase in TMSC but no difference in average annual pregnancy rate.


The risk of bias within and heterogeneity between studies assessing SCV correction are high, yet overall very little clinical benefit is derived from SCV correction.


Semen analysis Varicocele Pregnancy Meta-analysis Varicocelectomy 


Role of Funding Source

A.W.P. is a National Institutes of Health K12 Scholar supported by a Male Reproductive Health Research Career Development Physician-Scientist Award (HD073917-01) from the Eunice Kennedy Shriver National Institute of Child Health and Human Development Program (to Dolores J. Lamb).

Compliance with Ethical Standards

Conflict of Interest

Taylor P. Kohn, Samuel J. Ohlander, Jake S. Jacob, Tina M. Griffin, Larry I. Lipshultz, and Alexander W. Pastuszak each declare no potential conflicts of interest.

Human and Animal Rights and Informed Consent

This article does not contain any studies with human or animal subjects performed by any of the authors.


Papers of particular interest, published recently, have been highlighted as: • Of importance •• Of major importance

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Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2018

Authors and Affiliations

  • Taylor P. Kohn
    • 1
  • Samuel J. Ohlander
    • 2
  • Jake S. Jacob
    • 1
  • Tina M. Griffin
    • 3
  • Larry I. Lipshultz
    • 4
    • 5
  • Alexander W. Pastuszak
    • 4
    • 5
    • 6
  1. 1.Baylor College of MedicineHoustonUSA
  2. 2.Department of UrologyUniversity of Illinois Hospital and Health Sciences System at Chicago College of MedicineChicagoUSA
  3. 3.Library of Health SciencesUniversity of Illinois at ChicagoChicagoUSA
  4. 4.Scott Department of UrologyBaylor College of MedicineHoustonUSA
  5. 5.Center for Reproductive MedicineBaylor College of MedicineHoustonUSA
  6. 6.Center for Reproductive Medicine, Scott Department of UrologyBaylor College of MedicineHoustonUSA

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