Sperm abnormalities take a variety of forms and stem from different causes. When considering sperm production it is important to keep in mind that sperm are generated throughout a man’s lifetime and that the process takes about 70 days. Thus exposure to high temperature, which is harmful to sperm production, or another insult may manifest itself as low count or motility several weeks later.
Semen analysis is the primary test done to check for male factor. The normal sperm parameters are: volume above 2 mL, concentration (“count”) above 20 million/mL, initial motility above 50% and normal morphology above 4% by strict criteria. These numbers calculate to a minimum of 10 million moving sperm per ejaculate. Men whose ejaculates contain 5 or more million moving sperm per ejaculate are candidates for intra-uterine insemination (IUI). Men who ejaculate less than 4 million moving sperm at a time are more likely to require ICSI-IVF.
While semen analysis is the cornerstone of diagnosis, what really matters is the ability of sperm to fertilize eggs, which is much harder to assess. History of prior pregnancies may be helpful but, in its absence, IVF represents the ultimate “test” of sperm fertilizing capacity. ICSI is the primary treatment for sperm which cannot fertilize eggs on their own (What is ICSI? IVF Primer - ICSI)
Low sperm concentration and motility are the most common form of male factor. Some of these cases are associated with the presence of a varicocoele which is a dilated plexus of veins draining the testes. Surgical ligation or radiologic occlusion of a varicocele may improve sperm parameters and lead to conception provided there are no complicating female factors. Medical therapy has not usually been of help although an empirical trial of clomiphene has few downsides.
If the ejaculate lacks sperm, the condition may be due to either obstruction, such as following a vasectomy procedure, or failure of sperm production in the testes. The former condition is known as obstructive azoospermia and it is the primary indication for MESA procedure (What is MESA?)