Sperm Testing

Background about male fertility and sperm problems

About 25% of all infertility is caused by a male problem, and in 40-50% of cases it is the main cause, or a contributing cause.

It is sometimes hard to know whether the male factor problem is the only cause, or just a contributing cause to the infertility. Part of the problem is that numbers are just numbers:

  • Men with very low sperm counts and low motility scores can sometimes have children
  • Some men with normal counts are infertile without using IVF and ICSI

What matters is not really how many or how fast they swim - but whether they can fertilize the female partner's eggs. This is really a biochemical issue at the molecular level.

Therefore, looking at the little swimmers under the microscope is not always a perfect way of assessing the ability of the sperm to fertilize the female's eggs.

This is a very simple and important test and should be done early in the evaluation process. Sometimes the test should be done 2, or even 3 times to get an accurate reflection of the numbers and their variation over time.

The most important parameters in a semen analysis are:

Concentration (often called "count") - how many sperm are in each ml of semen?

Motility - what percent of them are swimming forward?

Morphology - what percent of them are normally shaped?

If a severe male factor defect is found, the amount of testing on the female is often reduced. Treatments, such as inseminations or in vitro fertilization can then be started more directly.

In some cases we do hormone (blood) tests on men with abnormal semen analysis. This can (rarely) sometimes identify a reason for the abnormality. Occasionally, the problem will be treatable in the male.


In some cases the man is referred to a urologist to assess whether he might have a correctable condition called a varicocele. However, correcting a varicocele (surgical procedure) often does not improve the semen quality enough to change the therapy that will be required to result in pregnancy.