by Anjali Malpani
Semen Analysis & Sperm
important test for assessing male fertility is the semen analysis. The
fact that it is so inexpensive can be misleading, because many patients (
and doctors ! ) feel that it must be a very easy test to do if it is so
cheap, which is why they get it done at the neighbourhood lab. However,
its apparent simplicity can be very misleading, because in reality it
requires a lot of skill to perform a semen analysis accurately. However,
it is very easy to do this test badly (as it often is by poorly trained
technicians in small laboratories), with the result that the report can
be very misleading - leading to confusion and angst for both patient
and doctor. This is why it is crucial to go to a reliable andrology
laboratory , which specialises in sperm ( Sperm Video ) testing, for your semen
analysis, since the reporting is very subjective and depends upon the
skill of the technician in the lab.
Some men try to judge their
fertility by the thickness of their semen. It's not possible to do this,
so don't worry if you think your semen is too "thin" or too fluid !
a semen analysis, a fresh semen sample, not more than half an hour old
is needed, after sexual abstinence for at least 3 to 4 days. The man
masturbates into a clean, wide mouthed bottle which is then delivered to
Providing a semen sample by masturbation can be
very stressful for some men - especially when they know their counts are
low; or if they have had problems with masturbation "on demand" for
semen analysis in the past. Men who have this problem can and should ask
for help. Either their wife can help them to provide a sample _ or they
can see sexually arousing pictures or use a mechanical vibrator to help
them get an erection. Some men also find it helpful to use liquid
paraffin to provide lubrication during masturbation. For some men, using
the medicine called Viagra can help them to get an erection, thus
providing additional assistance. If the problem still persists, it is
possible to collect the ejaculate in a special silicone condom (which is
non-toxic to the sperm and is available from our online store ) during sexual
intercourse, and then send this to the laboratory for testing.
semen sample must be kept at room temperature; and the container must
be spotlessly clean. If the sample spills or leaks out, the test is
invalid and needs to be repeated. Except for liquid paraffin, no other
lubricant should be used during masturbation for semen analysis - many
of these can kill the sperm. It is preferable that the sample is
produced in the clinic itself - and most infertility centres will have a
special private room to allow you to do so - a "masturbatorium".
How is the test performed in the laboratory?
waiting for about 30 minutes after ejaculation, to allow the semen to
liquefy, the doctor will check the semen.
The volume of the ejaculate. While a lot of
men feel their semen is "too little or not enough" , abnormalities of
volume are not very common. They usually reflect a problem with the
accessory glands - the seminal vesicles and prostate - which are what
produce the seminal fluid. Normal volume is about 2 to 6 ml. A low
volume ( less than 1 ml) is an uncommon problem, and is often due to
incomplete ejaculation ( which is not rare because of the stress of
producing a sample in the lab !) or spillage. Since the major portion of
the ejaculate is produced in the seminal vesicles, a persistently low
volume is because of a problem with seminal vesicle function - either
absence of the seminal vesicles, or an ejaculatory duct obstruction. A
very high volume surprisingly will also cause problems, because this
dilutes the total sperm present, decreasing their concentration.
The viscosity. During ejaculation the semen
spurts out as a liquid which gels promptly. This should liquefy again in
about 30 minutes to allow the sperm free motility. If it fails to do
so, or if it is very thick in consistency even after liquefaction, this
suggests a problem most usually one of infection of the seminal vesicles
Normally the pH of semen is alkaline because of the seminal vesicle
secretion. An alkaline pH protects the sperm from the acidity of the
vaginal fluid. An acidic pH suggests problems with seminal vesicle
function , and is usually found in association with a low volume of the
ejaculate and the absence of fructose.
presence of a sugar called fructose . This sugar is produced by
the seminal vesicles and provides energy for sperm motility. Its absence
suggests a block in the male reproductive tract at the level of the
examination The most important test is the visual examination of
the sample under the microscope. What do sperm look like ? Sperm are
microscopic creatures which look like tiny tadpoles swimming about at a
frantic pace. Each sperm has a head, which contains the genetic material
of the father in its nucleus; and a tail which lashes back and forth to
propel the sperm along. The mid-piece of the sperm contains
mitochondria, (the power house of the sperm) which provide the energy
for sperm motion.
Ask to see the sperm sample for yourself under
the microscope - if normal, the sight of all those sperm swimming around
can be very reassuring . You are likely to be awestruck by the massive
numbers and the frenzy of activity. If the test is abnormal, seeing for
yourself gives you a much better idea of what the problem is ! A good
lab should be willing to show you, and to explain the problem to you.
Sperm count ( concentration) . First the
doctor checks to see if there are enough sperm. This is done using a
specially calibrated counting chamber. 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.
motility ( whether the sperm are moving well or not ). 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 which move
forward fast are able to swim up to the egg and fertilise it - the
others are of little use. Motility is graded from a to d, according to
the World Health Organisation ( WHO) Manual criteria , as follows. Grade
a ( fast progressive) sperm are those which 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 ( nonprogressive) 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 fertilise the egg.
Sperm shape ( 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 fertilise 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 upto 85% abnormal forms is considered to
be acceptable!) Some men are infertile because most of their sperm are
abnormally shaped . This is called teratozoospermia ( terato=monster).
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 upto 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
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.
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 standardised, and vary from lab to
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 fertilising the egg.
The only foolproof way of proving whether the sperm work is by doing IVF
(in vitro fertilization) !
Azoospermia ( no sperm in the semen)
10% of infertile men will have no sperm at all in the semen. This is
called azoospermia . The conditions which cause azoospermia can be
classified into 3 groups - pre-testicular, testicular and
post-testicular. An example of azoospermia because of pretesticular
disease is hypogonadotropic hypogonadism, where the testis does not
produce sperm because of the absence of production of gonadotropins by
the pituitary. Consequently, even though the testes are normal, no sperm
are produced because of the absence of the needed hormonal stimulation.
In testicular conditions, the testis does not produce sperm because of
testicular failure ( end-organ damage). In these men, the testicular
damage is so severe that no sperm are found in the semen. This is also
called non-obstructive azoospermia, and an example of this is
Klinefelter's syndrome. In post-testicular conditions, even though sperm
are being produced normally in the testes, the outflow passage is
blocked (ductal obstruction or obstructive azoospermia)
a semen report shows azoospermia, then it needs to be rechecked. The
lab should be instructed to centrifuge the sample in order to look
carefully for sperm. A close analysis of the report will often help the
doctor to differentiate between non-obstructive and obstructive
azoospermia . Thus, if the semen volume is low, the pH is acidic and the
fructose is negative, then this is likely to be due to an obstruction
at the level of the ejaculatory duct. If sperm precursor cells (
immature sperm cells) are seen in the sample on careful microscopic
examination, then this clearly means that the problem is not because of
We request men with azoospermia to provide a
sequential ejaculate for semen analysis - two samples, produced 1-2
hours apart. Occasionally, in men with non-obstructive azoospermia, the
second sample may show a few sperm, because it is "fresher".
FSH level test in the blood ( as described in the next chapter) is also
helpful in differentiating between obstruction and testicular failure.
If the FSH level is high, it means the problem is testicular failure.
If, on the other hand, the FSH level is normal, then a testis biopsy is
needed to come to the correct diagnosis.
Rarely, some men will not
be able to ejaculate at all. This is called aspermia , and their semen
volume is zero. While this is sometimes because of a psychologic problem
( because the man cannot achieve an orgasm inspite of being able to get
an erection), the commonest reason for this is condition is retrograde
Poor sperm tests can result from incorrect semen
collection technique, if the sample is not collected properly, or if the
container is dirty too long a time delay between providing the sample
and its testing in the laboratory too short an interval since the
previous ejaculation recent systemic illness in the last 3 months (even a
flu or a fever can temporarily depress sperm counts)
sperm test is abnormal, this will need to be repeated 3-4 times over a
period of 3-6 months to confirm whether the abnormality is persistent or
not . Don't jump to a conclusion based on just one report - remember
that sperm counts do tend to vary on their own ! It takes six weeks for
the testes to produce new sperm - which is why you need to wait before
repeating the test. It also makes sense to repeat it from another
laboratory to ensure that the report is valid.
This is what
the doctor sees when he checks your semen sample under the microscope.