Male infertility is either due to a problem making good quality sperm, or a problem with delivery of the sperm to the outside world.
In 75% of infertile men, the cause remains unexplained (this is termed “idiopathic infertility”). It may, however, still be possible for couples to conceive naturally, provided some sperms are present.
Typical causes of delivery problems can range from issues with erections or ejaculation, to physical blockages, which can occur at any step from where the sperm is made in the testicle, to its point of delivery at the tip of the penis. Some blockages can be more easily overcome, such as a previous vasectomy. Others, such as multi-level obstruction due to infections, or being born without a vas tube cannot.
Issues that can cause problems with how sperm are made include:
The damage associated with some of these situations may be reversed to allow a return to normal fertility. Genetic problems cannot be reversed, but may be overcome using direct surgical sperm retrieval from the testicle.