Medihub - Medical Information - Urology

The male factor as a cause for subfertility is suspected when the couple has tried beyond 1 year and the wife has been evaluated to have normal reproductive organs and regular cycles. In 50% of these infertile couples, investigations will reveal that pathology is found in the woman alone. In another 20%, both the man and woman are abnormal. In the remaining 30%, male factor is solely responsible.

Conception requires the meeting and fertilisation of a healthy egg by a healthy sperm. This event requires the timely release of the ovum and timely deposition of semen in the vagina. The chance of any spermatozoon reaching the ovum is a function of their quantity, quality and the ability to penetrate into the egg. Evaluation of the infertile couple should therefore involve the couple from the outset until an abnormality is uncovered. An abnormal sperm count is usually the earliest indicator of a male factor.

The production of spermatozoa requires normal levels of sex hormones. Production of sex hormones is principally regulated by the pituitary gland of the brain. Conditions that affect the pituitary gland, may result in infertility, sometimes with impotence too.

Other causes of hormone imbalance include liver diseases, and steroid medications. Defective spermatozoa production can also occur without any apparent hormonal imbalance. Many of these cases are due to genetic disorders.

Causes
1. Congenital / genetic. Chromosomal defects like Klinefelter's syndrome, Noonan's syndrome, congenital adrenal hyperplasia and absent testes are congenital causes. Undescended testes tend to also be defective functionally and are generally poor producers of spermatozoa.

2. Acquired. Sperm production can also be affected by previous chemotherapy, radiotherapy, drug abuse (eg. marijuana, heroine), certain medications (cimetidine, spironolactone, ketoconazole), previous trauma, chronic renal failure, cigarette smoking and excessive alcohol consumption.

Spermatozoa production normally takes place in the testes at a temperature 1 degree C below normal body temperature. Tight pants and frequent hot baths may impair testicular temperature regulation and sperm production.

Mumps, a common childhood viral infection, can cause a severe testicular damage when caught after puberty and when both testicles are infected. Varicocoele, a condition of dilated and tortuous veins within the scrotum, is also known to cause subfertility, possibly because of venous congestion and testicular warming [Fig 1].
Fig 1. Varicocoele is the collection of dilated veins in the scrotum, which in turn, raise the temperature within the testicle
Finally, retrograde ejaculation of semen into the bladder can result in low sperm numbers being deposited in the vagina. This is commonly seen in diabetics.

Evaluation
After the history taking, a general physical examination, including the scrotum is done. Next, a blood test for hormone assay and a semen analysis is taken. An inadequate volume usually suggests a blocked vas while an inadequate concentration of spermatozoa suggests impaired spermatozoa production.

A complete absence of spermatozoa in the presence of small, poorly developed testes indicates primary testicular failure while a complete absence of spermatozoa in the presence of normal testes suggests vas obstruction, particularly when the hormone profile is normal.

If blockage of the vas is suspected, a transrectal ultrasound scan of the seminal vesicles and ejaculatory ducts is done; these structures would distended and dilated if there is an obstruction of the ejaculatory duct. If these structures are normal, surgical exploration of the testes to obtain a biopsy, harvest mature sperms for freezing and future assisted reproduction, and corrective surgery if it is possible to relieve the blockage .

Management
Treatment can only be initiated after clinical assessment and laboratory investigations are completed. The couple will be advised on possible corrective procedures and whether there is any need to proceed to costly assisted conception techniques.

1. Medication. If the hormonal assays are found to be normal, then supplements in the form of vitamins or swiss oats may be tried for a few months. Coupled with this is the need for lifestyle change, especially cessation of smoking, alcohol, or hot baths. Hormonal abnormalities, if identified, may need referral to an endocrinologist.

2. Varicocoele ligation. If a varicocoele is the only identifiable factor found, most urologists would advise surgery to ligate these big veins. This operation improves the semen quality in about two-thirds of men and may double the chance of conception. The reason for a non-improvement in a proportion of men is because of simultaneous defective sperm production from a genetic defect in the testes. Hence, a testicular biopsy is also done at the same time to determine the state of the sperm-producing cells.

3. Surgical exploration of the scrotum. This is indicated if obstruction is suspected or when the cause of absence of spermatozoa is in doubt. Testicular biopsy can be carried out to assess the function of sperm production and vasography xray to rule out obstruction. Corrective procedures can then be carried out to unblock or bypass the site of obstruction.

4. Surgery for obstructed ejaculatory ducts. If ejaculatory ducts are confirmed to be blocked at its opening into the urethra, they are best dealt by transurethrally resection (called TURED). Under anaesthesia, a resectoscope is inserted into the urethra and the opening of the ejaculatory ducts are incised under direct vision. Provided re-blockage does not occur, this procedure can result in marked improvement in semen parameters, and pregnancies have been achieved.

Retrograde ejaculation is more difficult to treat. If semen quality remains poor, spermatozoa can be retrieved from the urine voided immediately after ejaculation either for direct insemination or used in one of many assisted conception techniques. The urine needs to be rendered alkaline to avoid damage to the spermatozoa.

Modern fertility centres offer a variety of assisted conception techniques including procedures such as in vitro fertilisation (IVF), gamete intrafallopian transfer (GIFT) and intracytoplasmic sperm injection (ICSI) which have boosted the conception rate. As a result of these developments, more and more infertile men can hope to father their own children. For example, in ICSI, it involves the direct injection of a single spermatozoon into the egg for fertilization [Fig 2]. Even in patients with an uncorrectable obstruction of the reproductive tract, spermatozoa can be directly aspirated from the epididymis with the help of operating microscopes [Fig 3].
Fig 2. ICSI. A single sperm is injected directly into the egg to improve the chances of fertilization.

Fig 3. Aspiration of sperms from the epididymis