Clinic Location & Map

#09-40 Mt Elizabeth Novena Specialist Centre
(located within Mt Elizabeth Novena Hospital)
38 Irrawaddy Road
Singapore 329563

Phone: +65 6235 1180
Fax: +65 668 41310
Emergency: +65 6535 8833

Clinic Hours

Monday - Friday 9:00am - 5:30pm
Saturday 9:00am -12:30pm
Sunday / Public Holiday Closed

Male Infertility

Picture of Male Infertility

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 a pathology in the woman alone. In another 20%, the abnormality lies in both the man and woman. In the remaining 30%, the problem lies in the husband.

Conception requires fertilisation of a healthy egg by a healthy sperm. This requires the timely release of the ovum and deposition of semen in the vagina. The chance of any spermatozoa reaching the ovum is a function of their quantity, quality and the ability to penetrate 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 disease and steroid medications. Defective spermatozoa production can also occur without any apparent hormonal imbalance. Many of these cases are due to genetic disorders.


Picture of Varicocoele

Fig 1. Varicocoele is the collection of dilated veins in the scrotum. This tends to raise the temperature within the testicle and affect sperm production

  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 be functionally defective and poor producers of spermatozoa.
  2. Acquired. Sperm production can be affected by previous chemotherapy, radiotherapy, drug abuse (eg. marijuana, heroine), certain medications (cimetidine, spironolactone, ketoconazole), previous trauma, chronic renal failure, cigarette smoking and excess 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 when both testicles are infected. Varicocoele, a condition of dilated and tortuous veins within the scrotum, is also a common cause for subfertility, possibly because of venous congestion and testicular warmth [Fig 1].

Finally, retrograde ejaculation of semen into the bladder can result in low or no sperms deposited in the vagina. This is usually seen in diabetic men.


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. A low semen volume usually suggests a blocked vas while an inadequate concentration of spermatozoa suggests impaired 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 so if 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 be distended and dilated if there is an obstruction of the ejaculatory duct. If these structures are normal, surgical exploration of the testes is needed to obtain a biopsy, harvest mature sperms for freezing for future assisted reproduction, and if possible, corrective surgery done to bypass or relieve any blockage.


Treatment can only be initiated after clinical assessment and laboratory investigations have been completed. The couple will be advised on possible corrective procedures and whether to go on to costly assisted conception techniques.

  1. Medication. If the hormonal assays are normal, then supplements eg. vitamins A,C and E may be taken 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 varicocoele is the only identifiable factor found, most urologists would advise surgery to ligate these big veins. However, the varicocoele ought to be obvious clinically and found in both sides of the scrotum (as reported by independent ultrasound assessment). Assuming that the ligation is complete with no recurrence, the semen quality should improve by 6 months. If not, then the more likely cause is a simultaneous genetic defect in sperm producing cells of the testicles. Hence, a testicular biopsy is usually done at the same time to determine the state of the sperm production within the testicle.
  3. Surgical exploration of the scrotum. This is indicated if obstruction is suspected or when the cause of absent spermatozoa is in doubt. Corrective procedures can be carried out to unblock or bypass the site of obstruction. Testicular biopsy can be carried out to assess the function of sperm production and vasography to rule out obstruction. Sperm retrieval is done at the same sitting and stored for future assisted reproduction.
  4. Surgery for obstructed ejaculatory ducts. If ejaculatory ducts are confirmed to be blocked at its opening into the urethra, they are dealt by transurethrally resection (called TURED). Under anaesthesia, a resectoscope is inserted into the urethra and the opening of the ejaculatory ducts incised under direct vision. Provided re-blockage does not occur, this procedure can result in marked improvement in the sperm count.

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.

Picture of ICSI

Fig 3. ICSI. A single sperm is injected directly into the egg to improve the chances of fertilization.

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) where a single spermatozoon is injected into the egg to boost the conception rate [Fig 3]. As a result of these developments, infertile men can hope to father their own children.