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Saturday, March 29, 2008

MALE INFERTILITY

Male factors can be a cause of infertility in couples. About 4 percent of men will have significantly abnormal semen tests. However, not all men with abnormal semen tests will have problems conceiving.

Factors relating to male infertility include:

Pretesticular causes
- Endocrine problems, ie. diabetes mellitus, thyroid disorders
- Hypothalamic disorders, ie. Kallmann syndrome
- Hyperprolactinaemia
- Hypopituitarism
- Hypogonadism due to various causes
- Drugs, alcohol

Testicular factors
- Genetic defects on the Y chromosome
+ Y chromosome microdeletions
- Abnormal set of chromosomes
+ Klinefelter syndrome
- Neoplasm, e.g. seminoma
- Idiopathic failure
- Cryptorchidism
- Varicocele
- Trauma
- Hydrocele
- Mumps
- Testicular dysgenesis syndrome

Posttesticular causes
- Vas deferens obstruction
- Infection, eg. prostatitis
- Retrograde ejaculation
- Hypospadias
- Impotence
- Acrosomal defect/egg penetration defect

Smoking
- According to a study conducted by the American Society for Reproductive Medicine, smoking is one of the most prominent factors contributing to low sperm count in men.

Some causes of male infertility can be determined by analysis of the ejaculate, which contains the sperm. The analysis includes counting the number of sperm and measuring their motility under a microscope:

Abnormal sperm production

- producing few sperm (oligospermia)
- producing no sperm (azoospermia)
- poor sperm motility (asthenozoospermia)

In the majority of cases of male infertility and low sperm quality, no clear cause can be identified with current diagnostic methods.

Symptoms & signs

The history should include prior testicular insults (torsion, cryptorchidism, trauma), infections (mumps orchitis, epididymitis), environmental factors (excessive heat, radiation, chemotherapy), medications (anabolic steroids, cimetidine, and spironolactone may affect spermatogenesis; phenytoin may lower FSH; sulfasalazine and nitrofurantoin affect sperm motility), and drugs (alcohol, smoking).

Sexual habits, frequency and timing of intercourse, use of lubricants, and each partner's previous fertility experiences are important. Loss of libido and headaches or visual disturbances may indicate a pituitary tumour.

The past medical or surgical history may reveal thyroid or liver disease (abnormalities of spermatogenesis), diabetic neuropathy (retrograde ejaculation), radical pelvic or retroperitoneal surgery (absent seminal emission secondary to sympathetic nerve injury), or hernia repair (damage to the vas deferens or testicular blood supply).

Diagnosis

The diagnosis of infertility begins with a medical history and physical exam. The provider may order blood tests to look for hormone imbalances or disease. A semen sample may be needed. The volume of the semen is measured, as well as the number of sperm in the sample. How well the sperm move is also assessed.

The cornerstone of the male partner evaluation is the history. It should note the duration of infertility, earlier pregnancies with present or past partners, and whether there was previous difficulty with conception.

A complete examination of the infertile male is important to identify general health issues associated with infertility. For example, the patient should be adequately virilized; signs of decreased body hair or gynecomastia may suggest androgen deficiency.

The scrotal contents should be carefully palpated with the patient standing. As it is often psychologically uncomfortable for young men to be examined, one helpful hint is to make the examination as efficient and as matter of fact as possible.

The peritesticular area should also be examined. Irregularities of the epididymis, located posterior-lateral to the testis, include induration, tenderness, or cysts.

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