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Infertility in Men


General Information


  • infertility typically defined as inability to conceive after 1 year of unprotected sexual intercourse1,3,4,5
  • infertility in couples may be multifactorial and may include1
    • male factor infertility alone in about 30%
    • ovulation disorders in about 25%
    • tubal factors in about 20%
    • uterine or peritoneal disorders in about 10%
    • combined male and female factors in about 40%
    • unexplained (no identified male or female causes) in about 25%

Also called

  • subfertility


  • azoospermia defined as complete absence of sperm cells in ejaculate2
  • oligozoospermia (oligospermia)2,4
    • defined as decreased number of sperm cells
    • characterized by spermatozoa < 15 million/mL (severe oligozoospermia characterized by spermatozoa < 1 million/mL)
  • asthenozoospermia (asthenospermia)4
    • defined as decreased sperm motility
    • characterized by < 32% motile spermatozoa
  • teratozoospermia4
    • defined as many abnormal forms of sperm
    • characterized by < 4% normal forms
  • oligo-astheno-teratozoospermia (OAT) syndrome characterized by combination of sperm abnormalities4
  • mild male factor infertility1
    • term used extensively in practice but not formally defined
    • defined in National Health and Care Excellence (NICE) guideline as ≥ 2 semen analyses with ≥ 1 variable below fifth percentile


General references used

  1. National Institute for Health and Clinical Excellence (NICE). Guideline on assessment and treatment for people with fertility problems. NICE 2013 Feb 20:CG156OpenInNewPDFPictureAsPdf, summary can be found in BMJ 2013 Feb 20;346:f650OpenInNew
  2. Esteves SC, Hamada A, Kondray V, Pitchika A, Agarwal A. What every gynecologist should know about male infertility: an update. Arch Gynecol Obstet. 2012 Jul;286(1):217-29OpenInNew
  3. Hwang K, Walters RC, Lipshultz LI. Contemporary concepts in the evaluation and management of male infertility. Nat Rev Urol. 2011 Feb;8(2):86-94OpenInNewfull-textOpenInNew
  4. European Association of Urology (EAU). Guidelines on male infertility. EAU 2015 Mar PDFPictureAsPdf
  5. Practice Committee of the American Society for Reproductive Medicine. Diagnostic evaluation of the infertile male: a committee opinion. Fertil Steril. 2015 Mar;103(3):e18-25OpenInNew
  6. Cocuzza M, Agarwal A. Nonsurgical treatment of male infertility: specific and empiric therapy. Biologics. 2007 Sep;1(3):259-69OpenInNewfull-textOpenInNew
  7. Lee HS, Seo JT. Advances in surgical treatment of male infertility. World J Mens Health. 2012 Aug;30(2):108-13OpenInNewfull-textOpenInNew

Recommendation grading systems used

  • European Association of Urology (EAU) grading system for recommendations
    • grades of recommendation (which may be changed if panel consensus)
      • Grade A - based on clinical studies of good quality and consistency addressing the specific recommendations and includes ≥ 1 randomized trial
      • Grade B - based on well-conducted clinical studies, but without randomized clinical trials
      • Grade C - made despite the absence of directly applicable clinical studies of good quality
    • levels of evidence
      • Level 1a - meta-analysis of randomized trials
      • Level 1b - ≥ 1 randomized trial
      • Level 2a - ≥ 1 well-designed controlled study without randomization
      • Level 2b - ≥ 1 other type of well-designed quasi-experimental study
      • Level 3 - well-designed nonexperimental studies; such as comparative studies, correlation studies, and case reports
      • Level 4 - expert committee reports or opinions or clinical experience of respected authorities
  • Endocrine Society uses Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system
    • strength of recommendation
      • Strong recommendation - guideline panel members have high confidence that desirable effects of recommendation outweigh undesirable effects (or vice versa)
      • Weak recommendation - guideline panel members conclude with less confidence that desirable effects of recommendation probably outweigh undesirable effects, or benefits and harms are finely balanced, or appreciable uncertainty
    • quality of evidence
      • High-quality evidence - consistent evidence from well-performed randomized controlled trials, or exceptionally strong evidence from unbiased observational studies
      • Moderate-quality evidence - randomized controlled trials with important limitations (inconsistent results, methodological flaws, indirect or imprecise evidence), or unusually strong evidence from unbiased observational studies
      • Low-quality evidence - ≥ 1 critical outcome from observational studies, randomized controlled trials with serious flaws, or indirect evidence
      • Very low-quality evidence - ≥ 1 of the critical outcomes from unsystematic clinical observations or very indirect evidence

Synthesized Recommendation Grading System for DynaMed

  • DynaMed systematically monitors clinical evidence to continuously provide a synthesis of the most valid relevant evidence to support clinical decision-making (see 7-Step Evidence-Based MethodologyOpenInNew).
  • Guideline recommendations summarized in the body of a DynaMed topic are provided with the recommendation grading system used in the original guideline(s), and allow DynaMed users to quickly see where guidelines agree and where guidelines differ from each other and from the current evidence.
  • In DynaMed (DM), we synthesize the current evidence, current guidelines from leading authorities, and clinical expertise to provide recommendations to support clinical decision-making in the Overview & Recommendations section.
  • We use the Grading of Recommendations Assessment, Development and Evaluation (GRADE)OpenInNew to classify synthesized recommendations as Strong or Weak.
    • Strong recommendations are used when, based on the available evidence, clinicians (without conflicts of interest) consistently have a high degree of confidence that the desirable consequences (health benefits, decreased costs and burdens) outweigh the undesirable consequences (harms, costs, burdens).
    • Weak recommendations are used when, based on the available evidence, clinicians believe that desirable and undesirable consequences are finely balanced, or appreciable uncertainty exists about the magnitude of expected consequences (benefits and harms). Weak recommendations are used when clinicians disagree in judgments of relative benefit and harm, or have limited confidence in their judgments. Weak recommendations are also used when the range of patient values and preferences suggests that informed patients are likely to make different choices.
  • DynaMed (DM) synthesized recommendations (in the Overview & Recommendations section) are determined with a systematic methodology:
    • Recommendations are initially drafted by clinical editors (including ≥ 1 with methodological expertise and ≥ 1 with content domain expertise) aware of the best current evidence for benefits and harms, and the recommendations from guidelines.
    • Recommendations are phrased to match the strength of recommendation. Strong recommendations use "should do" phrasing, or phrasing implying an expectation to perform the recommended action for most patients. Weak recommendations use "consider" or "suggested" phrasing.
    • Recommendations are explicitly labeled as Strong recommendations or Weak recommendations when a qualified group has explicitly deliberated on making such a recommendation. Group deliberation may occur during guideline development. When group deliberation occurs through DynaMed-initiated groups:
      • Clinical questions will be formulated using the PICO (Population, Intervention, Comparison, Outcome) framework for all outcomes of interest specific to the recommendation to be developed.
      • Systematic searches will be conducted for any clinical questions where systematic searches were not already completed through DynaMed content development.
      • Evidence will be summarized for recommendation panel review including for each outcome, the relative importance of the outcome, the estimated effects comparing intervention and comparison, the sample size, and the overall quality rating for the body of evidence.
      • Recommendation panel members will be selected to include at least 3 members that together have sufficient clinical expertise for the subject(s) pertinent to the recommendation, methodological expertise for the evidence being considered, and experience with guideline development.
      • All recommendation panel members must disclose any potential conflicts of interest (professional, intellectual, and financial), and will not be included for the specific panel if a significant conflict exists for the recommendation in question.
      • Panel members will make Strong recommendations if and only if there is consistent agreement in a high confidence in the likelihood that desirable consequences outweigh undesirable consequences across the majority of expected patient values and preferences. Panel members will make Weak recommendations if there is limited confidence (or inconsistent assessment or dissenting opinions) that desirable consequences outweigh undesirable consequences across the majority of expected patient values and preferences. No recommendation will be made if there is insufficient confidence to make a recommendation.
      • All steps in this process (including evidence summaries which were shared with the panel, and identification of panel members) will be transparent and accessible in support of the recommendation.
    • Recommendations are verified by ≥ 1 editor with methodological expertise, not involved in recommendation drafting or development, with explicit confirmation that Strong recommendations are adequately supported.
    • Recommendations are published only after consensus is established with agreement in phrasing and strength of recommendation by all editors.
    • If consensus cannot be reached then the recommendation can be published with a notation of "dissenting commentary" and the dissenting commentary is included in the topic details.
    • If recommendations are questioned during peer review or post publication by a qualified individual, or reevaluation is warranted based on new information detected through systematic literature surveillance, the recommendation is subject to additional internal review.

DynaMed Editorial Process

Special acknowledgements

  • The American College of Physicians (Marjorie Lazoff, MD, FACP; ACP Deputy Editor, Clinical Decision Resource) provided review in a collaborative effort to ensure DynaMed provides the most valid and clinically relevant information in internal medicine.
  • DynaMed topics are written and edited through the collaborative efforts of the above individuals. Deputy Editors, Section Editors, and Topic Editors are active in clinical or academic medical practice. Recommendations Editors are actively involved in development and/or evaluation of guidelines.
  • Editorial Team role definitions
    Topic Editors define the scope and focus of each topic by formulating a set of clinical questions and suggesting important guidelines, clinical trials, and other data to be addressed within each topic. Topic Editors also serve as consultants for the internal DynaMed Editorial Team during the writing and editing process, and review the final topic drafts prior to publication.
    Section Editors have similar responsibilities to Topic Editors but have a broader role that includes the review of multiple topics, oversight of Topic Editors, and systematic surveillance of the medical literature.
    Recommendations Editors provide explicit review of DynaMed Overview and Recommendations sections to ensure that all recommendations are sound, supported, and evidence-based. This process is described in "Synthesized Recommendation Grading."
    Deputy Editors are employees of DynaMed and oversee DynaMed internal publishing groups. Each is responsible for all content published within that group, including supervising topic development at all stages of the writing and editing process, final review of all topics prior to publication, and direction of an internal team.

How to cite

National Library of Medicine, or "Vancouver style" (International Committee of Medical Journal Editors):

  • DynaMed [Internet]. Ipswich (MA): EBSCO Information Services. 1995 - . Record No. T902812, Infertility in Men; [updated 2018 Nov 30, cited place cited date here]. Available from Registration and login required.


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