assessment of male factor fertility problems

If male factor fertility problems then suggested investigations are (1):

Semen analysis

• results of semen analysis conducted as part of an initial assessment with are compared with the following World Health Organization (WHO) reference values (see the WHO laboratory manual for the examination and processing of human semen). Normal values are defined as:
  • semen volume: 1.4 ml or more (95% confidence interval [CI] 1.3 to 1.5)
  • pH: 7.2 or more
  • sperm concentration: 16 million spermatozoa per ml or more (95% CI 15 to 18)
  • total sperm number: 39 million spermatozoa per ejaculate or more (95% CI 35 to 40)
  • total motility (percentage of progressive motility and non-progressive motility): 42% or more motile (95% CI 40 to 43)
  • progressive motility: 30% or more (95% CI 29 to 31)
  • vitality: 54% or more live spermatozoa (95% CI 50 to 56)
  • sperm morphology (percentage of normal forms): 4% or more (95% CI 3.9 to 4.0)

• the reference ranges quoted are only valid for the semen analysis tests outlined by the World Health Organization
  

• routine testing for antisperm antibodies should not be offered
  
• if the result of the first semen analysis is abnormal, offer a repeat confirmatory test
  • undertake repeat confirmatory tests ideally 3 months after the initial analysis to allow time for the cycle of spermatozoa formation to be completed
    • note that, if a gross spermatozoa deficiency (azoospermia or severe oligozoospermia) has been detected, undertake the repeat test as soon as possible

For men, and trans women and non-binary people with male reproductive organs who have 2 or more abnormal semen analyses:

• a physical examination of the scrotum and testes should be offered, and
• measuring serum testosterone and gonadotrophin levels should be considered

Sperm DNA integrity (fragmentation) testing should not be undertaken.

If idiopathic azoospermia, or a sperm concentration of less than 1 million per ml, then:

• test for Y chromosome microdeletion in men, and trans women and non-binary people with male reproductive organs

In men, and trans women and non-binary people with male reproductive organs who have idiopathic suspected obstructive azoospermia or a vasal abnormality, or both, on examination, then:

• test for cystic fibrosis transmembrane conductance regulator genetic mutations

In men, and trans women and non-binary people with male reproductive organs who have idiopathic azoospermia, then:

• test for karyotype abnormalities

In men, and trans women and non-binary people with male reproductive organs who have a persistent sperm concentration of less than 5 million per ml, then:

• consider testing for karyotype abnormalities

Appropriate genetic counselling for men, and trans women and non-binary people should be offered for those who have a specific genetic defect associated with male factor infertility.

Reference

1. NICE. Fertility problems: assessment and treatment. Clinical guideline CG156. Published February 2013, last updated March 2026