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Male Infertility

Male Infertility
14 March 2000 --

Dr Ng Min Ching
General Practitioner

Infertility is the total inability (sterility) or diminished ability to produce offspring. One in every six couples who are trying to achieve pregnancy suffers from it. Male and female abnormalities account for about a third each of infertility cases. The remaining third are due to abnormalities in both partners. In Singapore,
10-15% of couples are infertile.

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When a couple in unable to have a child, both partners need to be investigated. However, in our conservative Asian society, men are usually less willing than their wives to be investigated by doctors in infertility cases. It is important to convince the male to have a thorough check-up. This is especially so when the female has been given a clean bill of health.

It is also important to note that infertility is not to be confused with impotence, which is the inability to achieve and/or maintain an erection of the penis adequate for sexual intercourse.

Causes of infertility
Poor sperm quality and/or sperm production account for 80% of the causes. The remaining 20% are either mechanical or unknown disorders.

  • Brain causes, e.g. pituitary tumours, pituitary infections
  • Testicular causes

  • 1. Elevation in scrotal temperature.
    (i) Varicocele. This is the commonest cause of male infertility. A varicocele is a bunch of distended and tortuous testicular veins located on top of a testis. It feels like a bag of worms.

    The testis needs an optimal temperature (1 degree Celsius below body temperature) for sperm production and enzyme function. Raising the temperature by even one degree will adversely affect the testicular processes markedly.

    (ii) Undescended testis. The testis descends into the scrotum during foetal development. Failure to do so will result in the testis remaining in the abdomen, thereby subjecting the testis to body temperature.

    (iii) Hernia. This is an abnormal condition where part of the intestines protrudes into the scrotum.

    (iv) Febrile illnesses.

    (v) Tight underwear or clothes, frequent sauna baths.

    2. Chromosomal and structural defects

    3. Viral causes, e.g. mumps

    4. Trauma to the testis

5. Drugs
Certain antidepressants, antihypertensives are known to suppress sperm production heroin, marijuana

6. Excessive alcohol consumption
This decreases plasma testosterone (male sex hormone) and hence sperm production.

7. Smoking

8. Radiation
This is the reason why the male genitalia is always protected by a lead sheet when X-rays are done for other parts of the body.

9. Diseases such as liver disease, kidney failure

  • Obstruction to Sperm Transport

  • Sperms are being produced but they are unable to get out because of a blockade. The epididymis is a duct leading from the testis to the vas deferens. Urinary tract infections and sexually transmitted diseases are able to cause infection and subsequent scarring of the epididymis, resulting in an obstruction in sperm travel.

    Another cause of blockade is vasectomy. One percent of infertile males are born without the vas deferens.

  • Unknown causes

Investigation of the male
It is important to get a good history to elicit any possible causes of infertility. This will include the sexual history (e.g. erection, ejaculation, frequency of intercourse, whether penetration has been achieved), current medication, lifestyle factors (smoking, alcohol intake, habitual attire, stress) and past history of testicular infections or venereal diseases.

A thorough physical examination then follows. The male genitalia is carefully examined with particular attention paid to the size and consistency of the testes and epididymides, at the same time looking for varicoceles and hernia. A rectal examination is also done to assess whether the prostate is normal. Following these, the male is sent for a seminal fluid analysis.

The seminal analysis is the best laboratory test in the investigation of male infertility and one of the first tests carried out. If the result is abnormal, the cause of the infertility has most likely been diagnosed.

It is necessary to have at least two seminal fluid specimens before an accurate interpretation can be done. After 3-5 days abstinence from sex, a semen sample obtained by masturbation is collected in a sterile container and examined within two hours.

Average figures in seminal fluid analysis:
volume 2-6.5 ml
density 20-250 million sperms per ml
motility >40% progressively motile
morphology>50% normal sperms

Normal male fertility requires a sperm density of more than 20 million sperms per ml, a motility of over 40% and >50% normal sperms. The presence or absence of sperm antibodies, bacteria or virus can also be ascertained with this analysis.

Treatment in Singapore
The treatment of male infertility is difficult. However, recent advances have improved the outcome and helped more infertile couples succeed in their quest for their own offspring.

Eliminating adverse lifestyle factors will help to improve sperm count and function. Advising the patient to quit smoking, to decrease alcohol consumption, to avoid drugs that impair fertility, to wear loose underwear and to reduce stress all go towards improving the sperm quality.

Antibiotics are used for genital infections. Drugs such as testosterone, mesterolone, clomiphene and human chorionic gonadotrophin increase sperm production. Steroids are used if sperm antibodies are present.

Surgical therapy includes operative removal of varicoceles and surgical blockade repair of the epididymis. In a man who has had a vasectomy and has since regretted the decision, a vasectomy reversal will achieve good results.

Success rates for artificial techniques of reproduction such as IVF (in-vitro fertilisation) and GIFT (gamete intra-fallopian transfer) are low. With recent advances, a procedure developed in Belgium, known as ICSI (intracytoplasmic sperm injection) has allowed 90% of all infertile men to father their own children. In this technique, the sperm is injected directly into the egg.

If all else fails, the last resort would be donor insemination, where a donor's sperm is used to fertilise the wife's egg or adoption of a child.

Science is advancing rapidly in the treatment of male infertility. With time, more and more couples will be able to fulfil their desires to have their own babies.

Who to consult for male infertility
Patients will be referred to a specialist (urologist) by their general practitioners or polyclinic doctors.

Facts about female infertility


  1. Braunwald, Isselbacher, Petersdorf, Wilson, Martin and Fauci. Harrison's Principles of Internal Medicine, 11th edition, 1987. McGraw Hill International Edition.
  2. Centre for Male Reproductive Medicine and Microsurgery, www.maleinfertility.org/new-understanding.html

Date reviewed: 06 March 2000

This website and article is not a substitute for independent professional advice. Nothing contained in this website is intended to be used as medical advice and it is not intended to be used to diagnose, treat, cure or prevent any disease, nor should it be used for therapeutic purposes or as a substitute for your own health professional's advice.  All Health and any associated parties do not accept any liability for any injury, loss or damage incurred by use of or reliance on the information.


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