Further investigations of male infertility

Other tests may be considered if the semen analysis is abnormal or if the history and clinical examination are suggestive.

ENDOCRINE TESTS

In men with azoospermia serum FSH levels help to differentiate between obstructive and non-obstructive causes. Normal levels are indicative of obstructive azoospermia

Table 45.13 Methods for sperm retrieval

Procedure

Type of azoospermia

Comments

Percutaneous epididymal sperm aspiration (PESA) Testicular sperm aspiration (TESA) Testicular sperm extraction (TESE) Microsurgical sperm extraction (MESA)

Obstructive

Non-obstructive

Non-obstructive

Obstructive

Outpatient, under local anaesthetic

Outpatient, under local anaesthetic Under general anaesthetic Under general anaesthetic where surgical sperm retrieval may be considered while elevated levels are suggestive of failure of spermatogenesis (Table 45.13). In rare cases undetectable levels of FSH can be suggestive of hypogonadotrophic hypogonadism where treatment with exogenous FSH may be effective. Testosterone and LH measurements are helpful in the assessment of men where androgen deficiency is suspected or where there is a need to exclude sex steroid abuse or steroid secreting tumours of the testes or adrenals. As men with hyperprolactinaemia have sexual dysfunction, it is necessary to exclude elevated prolactin levels in men with loss of libido and impotence. Persistently elevated prolactin levels warrant further investigations such as imaging of the pituitary gland.

CHROMOSOMAL AND GENETIC STUDIES

Men with azoospermia or severe oligozoospermia should undergo chromosomal analysis. A cystic fibrosis screen should be performed for men with CBAVD which is associated with defects in the cystic fibrosis transmembrane conductance regulator (CFTR) gene.

MICROBIOLOGY OF SEMEN

The significance of asymptomatic infection of the male genital tract as demonstrated by white blood cells in the ejaculate is unclear. Semen culture is indicated in men with microscopic evidence of infection. Male partners of women with chlamydia infection should be screened.

IMAGING OF THE MALE GENITAL TRACT

A number of techniques have been used for imaging varic-oceles. Doubts about the justification of routine treatment for varicoceles have diminished the enthusiasm for these investigations. Although expensive, retrograde venogra-phy is the gold standard. Other tests include ultrasound and Doppler, radionucleotide angiography and thermog-raphy. Scrotal ultrasound scans are helpful if testicular tumours are suspected. In obstructive lesions of the male genital tract, vasography can be used to detect the site of obstruction. This is of limited clinical use with the advent of surgical sperm extraction and intracytoplasmic sperm injection.

IN VITRO TESTS OF SPERM FUNCTION

Introduction of assisted reproduction techniques such as IVF and ICSI has reduced the significance and clinical relevance of in vitro tests of sperm function including tests of acrosomereaction, zona binding and thezona freehamster egg penetration test (Table 45.14).

TESTICULAR BIOPSY

Testicular biopsy has been used in the past as a diagnostic tool to differentiate between obstructive and non-obstructiveazoospermia. Thereis limited scopefor theuse of this invasive technique whose benefits are outweighed by potential risks such as reduction of testicular mass, devascularization, fibrosis and autoimmune response.

ANTISPERM ANTIBODIES

Tests for antisperm antibodies are not routine. The presence of sperm agglutination should alert the laboratory to the potential presence of antisperm antibodies. Subsequent tests to be done on a fresh sample should include MAR (mixed agglutinin reaction) and the immunobead test.

MAR involves incubating semen with red blood cells coated with non-specific antibody to IgA or IgG (anti-IgA or anti-IgG). Sperm with antisperm antibodies will adhere to treated red blood cells.

The immunobead test relies on micron-sized polyacrylic beads with covalently bound albumin IgA and IgG antibodies. Binding of sperm with antisperm antibodies to the beads allows detection of the presence as well as the site of antibodies.

Pregnancy Guide

Pregnancy Guide

A Beginner's Guide to Healthy Pregnancy. If you suspect, or know, that you are pregnant, we ho pe you have already visited your doctor. Presuming that you have confirmed your suspicions and that this is your first child, or that you wish to take better care of yourself d uring pregnancy than you did during your other pregnancies; you have come to the right place.

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