Diagnosis

Semen analysis

Semen analysis provides information on semen volume, sperm motility, sperm morphology and any other cells present in the semen, for example white blood cells. Three specimens are usually required to produce an accurate analysis, and these are obtained by masturbation.

While semen analysis cannot provide definitive evidence of infertility, it does provide information on the hormonal status, spermatogenesis and the reproductive tract environment. For example, the presence of white blood cells may indicate an infection.

Hormonal evaluation

Hormonal evaluation is only required in cases where the number of sperm is very low, or if there is reason to suspect an endocrine problem. Levels of gonadotropin-releasing hormone, LH and FSH are all monitored in order to detect hypothalamic or pituitary problems. However, endocrine problems are rare in male infertility, and as a result hormonal evaluation is not routinely used in the diagnosis of infertility.

Chromosomal studies

These involve karyotyping the man’s genome in order to detect for genetic disorders that may be causing infertility. Genetic causes of male infertility can be divided into single gene defects or chromosomal defects. Chromosomal defects can then be further subdivided into numerical or structural defects.

Single gene defects resulting in male infertility include Kallmann’s syndrome, cystic fibrosis and congenital absence of the vas deferens. Kallmann’s syndrome is X-linked recessive, and results in a lack of gonadotropin releasing hormone secretion from the hypothalamus.Numerical chromosomal defects are when there is a change in the number of chromosomes. 

Klinefelter syndrome is caused by the presence of extra X chromosomes – 80% of cases are XXY, but some cases are XXXY, XXXXY or XXYY. Klinefelter's is characterised by a reduction in serum testosterone levels, azoospermia and small testicles. Physical examination and hormonal studies can be used to clarify this.

Immunological studies

Sperm are antigenic, which means they are foreign to the body and are therefore subject to attack by antibodies. The blood-testis barrier usually protects them, but this can breakdown, for example after a vasectomy. If this occurs, the sperm are then targeted by antibodies, which can result in decreased motility, the masking of receptors that recognise the egg and aid penetration, and an increase in phagocytosis by white blood cells.

Tests can be performed to look for the presence of sperm-attacking antibodies, most commonly IgA and IgG. If these are present it indicates a problem with the blood-testis barrier and may be the underlying cause of infertility.

It is also important to note that in some cases, infertility cannot be explained. Infertility can simply be due to the incompatability of the couple, or a combination of problems in either partner.