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If there are enough sperm under the microscope, the doctor checks to see. If the sample has less than 20 million sperm per ml, this is considered to be a low sperm count. Less than 10 million is very low. The technical term for this is oligospermia (oligo means few). Some men will have no sperm at all and are said to be azoospermic. This can come as a rude shock because the semen in these patients looks absolutely normal it is only on microscopic examination that the problem is detected.
Whether the sperm are moving well or not (sperm motility). The quality of the sperm is often more significant than the count. Sperm motility is the ability to move. Sperm are of two types - those which swim, and those which don't. Remember that only those sperm that move forward fast are able to swim up to the egg and fertilize it - the others are of little use. Motility is graded from a to d, according to the World Health Organization (WHO) Manual criteria, as follows. Grade a (fast progressive) sperm are those that swim forward fast in a straight line - like guided missiles. Grade b (slow progressive) sperm swim forward, but either in a curved or crooked line, or slowly (slow linear or non linear motility). Grade c (non progressive) sperm move their tails, but do not move forward (local motility only). Grade d (immotile) sperm do not move at all. Sperm of grade c and d are considered poor. Why do we worry about poor motility? If motility is poor, this suggests that the testis is producing poor quality sperm and is not functioning properly - and this may mean that even the apparently normal motile sperm may not be able to fertilize the egg.
Whether the sperm are normally shaped or not what is called their form or morphology. Ideally, a good sperm should have a regular oval head, with a connecting mid-piece and a long straight tail. If too many sperms are abnormally shaped (round heads; pin heads; very large heads; double heads; absent tails) this may mean the sperm are abnormal and will not be able to fertilize the egg. Many labs use Kruger "strict " criteria (developed in South Africa) for judging sperm normality. Only sperm, which are "perfect", are considered to be normal. A normal sample should have at least 15% normal forms (which means that even up to 85% abnormal forms is considered to be acceptable!)
Sperm clumping or agglutination. Under the microscope, this is seen as the sperm sticking together to one another in bunches. This impairs sperm motility and prevents the sperm from swimming up to through the cervix towards the egg.Putting it all together, one looks for the total number of "good" sperm in the sample - the product of the total count, the progressively motile sperm and the normally shaped sperm. This gives the progressively motile normal sperm count, which is a crude index of the fertility potential of the sperm. Thus, for example, if a man has a total count of 40 million sperm per ml; of which 40% are progressively motile, and 60% are normally shaped; then his progressively motile normal sperm count is: 40 X 0.40 X 0.60 = 9.6 million sperm per ml. If the volume of the ejaculate is 3 ml, then the total motile sperm count in the entire sample is 9.6 X 3 = 28.8 million sperm.
Whether pus cells are present or not. While a few white blood cells in the semen is normal, many pus cells suggest the presence of seminal infection.
Some labs use a computer to do the semen analysis. This is called CASA, (computer assisted semen analysis). While it may appear to be more reliable (because the test has been done "objectively" by a computer), there are still many controversies about its real value, since many of the technical details have not been standardized, and vary from lab to lab.
A normal sperm report is reassuring, and usually does not need to be repeated. If the semen analysis is normal, most doctors will not even need to examine the man, since this is then superfluous. However, remember that just because the sperm count and motility are in the normal range, this does not necessarily mean that the man is "fertile". Even if the sperm display normal motility, this does not always mean that they are capable of "working" and fertilizing the egg. The only foolproof way of proving whether the sperm work is by doing IVF (in vitro fertilization)!
© Dr. Aniruddha Malpani and Dr. Anjali Malpani www.drmalpani.com
Credits: How to Have a Baby: Overcoming Infertility
