Male infer­tility: causes

Reduced male fertility

In most cases, a man’s fertility can easily be assessed with a semen analysis (although no semen analysis can predict it with 100% certainty). A semen analysis may show the following abnormalities:

• Low sperm count – oligospermia

A healthy man normally produces 15 million sperm per ml. A lower number means reduced fertility.

• No sperm production – azoospermia

Because of a malfunction of the testes or a blockage of the sperm ducts, the testes do not produce sperm. For sperm retrieval in azoospermia, read about the TESE and MESA methods.

• Reduced sperm motility – asthenospermia

The sperm do not move well enough to pass through the cervix and the uterine cavity and meet the egg in the fallopian tube.

• Abnormal shape (morphology) – teratospermia

Abnormally shaped sperm are unable to penetrate the outer layer of the egg.

Possible causes of reduced sperm quality

a. Disorders of sperm production as a result of:

• Infections (e.g. mumps)
• Undescended testis
• Varicocele
• Hormonal disorders
• Surgery, chemotherapy
• Radiation

Often the cause remains unknown (idiopathic).

b. Disorders of sperm transport as a result of:

• Surgery, infections, injuries
• Inherited anatomical abnormalities
• Ejaculation disorders

c. Genetic disorders
d. Lifestyle

• Stress, nicotine, a poor diet, environmental factors

Other causes

Apart from problems with the sperm, there are other causes of male infertility:

• Problems during sexual intercourse, e.g. erectile dysfunction, ejaculation disorders
• Immunological infertility, i.e. the woman’s body produces antibodies against the man’s sperm
• Previous sterilisation of the man (cutting of the sperm ducts, vasectomy)

Also read about the sperm DNA fragmentation (DFI) test and about intracytoplasmic sperm injection (ICSI).