About 30% of all cases of a couple’s infertility will be due to a male factor. A semen analysis is obtained after 3 days of abstinence to examine the male’s sperm for:
- The sperm count.
- The motility (ability to swim).
- The percentage of normal sperm in the sample.
- The presence of white blood cells indicating a possible infection or the presence of anti-sperm antibodies (see below).
After 2 abnormal semen analyses, male factor infertility will be grouped into the following causes.
Reduced Sperm potency
The vast majority of cases of male infertility are due to a low sperm count, which is generally associated with a high rate of sperm abnormalities (abnormality in size, shape, and motility of the sperm). Most often there is no cause identified for this. A prior history of mumps, genital trauma, undescended testes as a baby, and some medications may be responsible. Also, heavy alcohol use, smoking and drug use can affect sperm quality, as can being significantly overweight. There can sometimes changes to lifestyle and general health that can be made that can improve sperm quality, but most often fertility assistance will be required in the form of Intrauterine insemination (minor abnormality), In Vitro Fertilisation (IVF) or IVF and Intra-cytoplasmic injection of sperm (ICSI) into the eggs for a more severe sperm abnormality.
No sperm present (azoospermia)
Some men are found to have no sperm in their semen. This is due to either an issue with:
- Stimulation of the testes to produce sperm due to a hormonal problem
- Production of sperm due to abnormality inherent to the testes.
- A blockage in the vas deferens, which is the tube that brings sperm to the ejaculate.
The testes can fail to produce sperm due to a hormonal issue like an underactive pituitary gland, high prolactin from a small tumour on the pituitary gland, or suppression of sperm production due to use of testosterone supplements (i.e., anabolic steroids).
Inherent testicular issues preventing sperm production include chromosomal or genetic abnormalities, damage to the testes in the past from a severe infection like mumps, damage from prior surgery or trauma, or prior radiation for cancer etc.
The vas deferens can be blocked by prior vasectomy, a prior infection which damages and blocks the vas deferens (like what happens with the Fallopian tubes in the female), or failure of the vas deferens to develop in the first place, as happens in cystic fibrosis but can also occur independent of cystic fibrosis.
Much less common causes of male factor infertility include retrograde ejaculation, when the ejaculate of some men is diverted into the bladder, and anti-sperm antibodies, in which a small group of men actually produce antibodies against their own sperm.