Abnormalities in semen parameters accounts for approximately 20% of infertility cases and is a contributing diagnosis in another 20-40% of infertile couples. As a result, evaluation of sperm is a vital portion of the infertility work-up. This is performed by obtaining a semen sample from the ejaculate following masturbation after 2-3 days of abstinence.
WHO parameters of lower reference limits for semen analysis in fertile men includes:
- Volume: 1.5 (1.4-1.7) mL
- Concentration: 15 (12-16) million/mL
- Total sperm number: 39 (33-46) million/ejaculate
- Total motility: 40 (38-42) %
- Progressive motility: 32 (31-34) %
- Normal morphology: 4 (3-4) %
If the first semen analysis demonstrates abnormal results, it is often repeated. This is because there may be large variations between sperm samples and confirmation of largely abnormal semen analysis results is an important step to proceed with additional testing. Unfortunately, most causes of male infertility remain unknown and may not be amenable to treatment however a number of causes can be treated to improve pregnancy outcomes.