Male Infertility

written by Dr Loh Chit Sin on 7 April 2011

When should a couple be regarded as infertile?

80 - 85 % of couples would normally achieve a pregnancy after one year of unprotected intercourse. Although some pregnancy can still be achieved without medical intervention beyond 1 year of trying, couple who failed after this time are generally regarded as possibly infertile and medical evaluation should be considered.

Who is to blame?

In 50% of these infertile couples, investigation 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.

When should male factor be suspected?

Conception requires the meeting and fertilisation of a healthy ovum by a healthy spermatozoon. The likelihood of this happening in turn depends on the timely release of the ovum and timely deposition of semen in the vagina. The chance of any spermatozoon reaching the ovum in turn depends on their quantity, quality and the ease of them getting there. Evaluation of the infertile couple should therefore involve the couple as a unit and in parallel from the outset until an abnormality is uncovered. Evaluation is therefore best carried out in dedicated multidisciplinary units. An abnormal sperm count usually is the earliest indicator of a male factor.

What cause male factor infertility?

The production of spermatozoa requires a normal sex hormone balance. Production of sex hormones is principally regulated by a special gland at the base of the brain called the pituitary gland. This is in turn regulated by a part of the midbrain called the hypothalamus. Many conditions that affect the hypothalamus or pituitary gland, most of them congenital, may result in infertility, usually with concomitant impotence.   Other causes of hormone imbalance include liver diseases, steroid medications and certain testicular tumours that secret hormone. Defective spermatozoa production can also occur without any apparent hormonal imbalance. Many of these cases have been found to be due to genetic disorders.

Many intersex conditions are associated with a state of sterility. These include many chromosomal defects like Klinefelter's syndrome, Noonon's syndrome, undiagnosed congenital adrenal hyperplasia and congenitally absent testes. Spermatozoa production normally takes place in the testes, preferentially at a temperature slight below that of normal body temperature. Many experts believe that tight trousers impair testicular temperature regulation and contribute to infertility. Other testicular conditions afflicting both testes may result in infertility. Mumps, a common childhood viral infection, can cause a severe testicular damage when caught after puberty and results in infertility. Testes which do not descend normally are in some ways defective and are generally poor producer of spermatozoa. Capacity of sperm production can also be affected by previous chemotherapy, radiotherapy, drug abuse (marijuana, heroine, methadone etc.), certain medications (cimetidine, cyproterone, spironolactone, ketoconazole etc.), previous trauma, chronic renal failure and excessive alcohol consumption. Varicocele, a condition of dilated and tortuous veins within the scrotum, is also known to cause subfertility, possibly because of venous congestion and testicular warming.

From the testis, spermatozoa are transported to the epididymis, a structure closely related to the testis. Within the epididymis, spermatozoa mature and gain motility. The epididymis empties into a long tube call the vas deferens which transport the spermatozoa via the ejaculatory duct into the posterior urethra. During ejaculation, the bladder opening has to close to prevent semen from entering back into the bladder while the pelvic and urethra muscles contract in rhythmic fashion to squirt out the semen. Several infections, particularly those venereal in nature can result in inflammation, subsequent scarring and obstruction of the reproductive tract, typically at the level of the epididymis. Stricture of the urethra can impair semen delivery and hypospadias, a congenital condition of the urethra opening short of the tip of the penis, if severe, results in deposition of semen outside the vagina. Finally, failure of the baldder to close during ejaculation would result in retrograde ejaculation of semen into the bladder, instead of out of the urethra.

How would your urologist assess your fertility?

After a careful history, your urologist will proceed to a general physical examination, including examination of your external genitalia. Usually, your urologist would proceed to a blood test for hormone assay and a semen analysis. Although semen analysis is not a test of fertility, a carefully performed semen analysis is a highly predictive indicator of the functional status of the male reproductive hormonal cycle, spermatogenesis and the patency of the reproductive tract. Usually, an inadequate volume suggest a physically obstruction of the reproductive tract while an inadequate concentration of spermatozoa suggestion spermatozoa production problem. An excess of inflammatory cells in the ejaculate suggests infection of the reproductive tract. A complete absence of spermatozoa in the presence of small, poorly developed testes indicates primary testicular pathology while a complete absence of spermatozoa in the presence of normal testes suggests obstruction of the reproductive tract, particularly when the hormone profile is normal. Some urologists would carry out a transrectal ultrasound scan of the seminal vesicles and ejaculatory ducts and these structures would be found to be distended and dilated if there is an obstruction of the ejaculatory duct. If these structures are normal, most urologists would proceed to surgical exploration of the testes with a view for corrective surgery. Where indicated, serum and seminal anti-sperm antibodies can also be assayed to exclude a condition of autoimmunity by the body’s defence system against spermatozoa.

Specialised fertility centres are equipped to carry out more specific test to assess sperm quality. Computer-assisted semen analysis (CASA) systems allows some quantification of spermatozoal performance while more specific test are available to assess sperm viability, sperm-cervical mucus interaction and egg penetration. Most of these tests are carried out as part of the work up to assisted conception procedures.

How can a urologist help an infertile man?

After initial assessment and further laboratory investigations, a urologist should be in a position to counsel the infertile couple about treatment, possible corrective procedure and whether there is any need to proceed to costly assisted conception procedures. Hormonal abnormalities, if identified, will need attention and most of these are best dealt with by an endocrinologist. The existence of any uncorrectable congenital anomalies will be explained. If a varicocele is found to be associated with subnormal semen, most urologists would advise surgery to ligate the varicocele. This operation improves semen quality in about two-thirds of men and may double the chance of conception.

Surgical exploration is indicated for cases in which obstruction is suspected or in which the cause of absence of spermatozoa remains in doubt. Testicular biopsy can be carried out to assess the function of sperm production and X-ray carried out to rule out obstruction. Corrective procedures can be carried out to bypass identified obstruction of the reproductive tract.

Obstructed ejaculatory ducts are best dealt with transurethrally. Under anaesthesia a special telescope is inserted into the urethra and the opening of the ejaculatory ducts can be incised under direct vision from inside the urethra. This procedure has resulted in marked improvement in semen parameters, and pregnancies have been achieved.

Retrograde ejaculation is more difficult to treat. Causative medication should be stopped. 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 nowadays 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 has boost the conception rate. As a result of these developments, more and more infertile men can hope to father their own children. The last procedure for example, only require the direct injection of a single spermatozoon into the egg for fertilisation. As a result, urologists are obliged to try harder and harder to obtain spermatozoa for the technique. Thus, for patients with uncorrectable obstruction of the reproductive tract, spermatozoa can be directly aspirated from the epididymis with the help of operating microscopes.