from
the book How to Have a Baby: Overcoming Infertility
by Dr. Aniruddha Malpani, MD and Dr. Anjali Malpani,
MD.
Previous page:
Testing the
Man - Semen Analysis (Page 1)
Next page: Beyond
the Semen Analysis
Table of Contents
What
is a normal sperm count ?
What
is normal sperm motility ?
What
is normal sperm morphology ?
What
does the presence of pus cells in the semen signify
?
What
does a normal semen analysis report mean ?
What
are the reasons for a poor semen analysis report ?
What
if my sperm count is zero ( azoospermia) ?
Fig 2. The anatomy of
a sperm
What is a normal sperm count ?
If there are enough sperms.
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 sperms at all and are said to be azoospermic. This
can come as a rude shock because the semen in these
patients look absolutely normal - it is only on microscopic
examination that the problem is detected.
What is normal sperm motility
?
Whether the sperms are moving well
or not (sperm motility). The quality of the sperm
( Sperm Video ) is
often more significant than the count. Sperm ( Sperm Video ) motility
is the ability to move. Sperm are of 2 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) sperms are those
which swim forward fast in a straight line - like guided
missiles.
Grade b (slow progressive) sperms swim forward,
but either in a curved or crooked line, or slowly (slow
linear or non linear motility).
Grade c (nonprogressive) sperms move their
tails, but do not move forward (local motility only).
Grade d (immotile ) sperms do not move at all.
Sperms of grade c and d are considered
poor. If motility is poor
( this is called asthenospermia) , this suggests that
the testis is producing poor quality sperm and is not
functioning properly – and this may mean that even the
apparently motile sperm may not be able to fertilise
the egg.
This is why we worry when the motility
is only 20% (when it should be at least 50% ? ) Many
men with a low sperm count ask is - " But doctor, I
just need a single sperm to fertilise my wife's egg.
If my count is 10 million and motility is 20%, this
means I have 2 million motile sperm in my ejaculate
- why can't I get her pregnant ? " The problem is that
the sperm in infertile men with a low sperm count are
often not functionally competent - they cannot fertilise
the egg. The fact that only 20% of the sperm are motile
means that 80% are immotile - and if so many sperm (
Sperm Video ) cannot
even swim, one worries about the functional ability
of the remaining sperm. After all, if 80% of the television
sets produced in a factory are defective, no one is
going to buy one of the remaining 20% - even if they
seem to look normal.
What is normal sperm morphology
?
Whether the sperms are normally shaped
or not - what is called their form or morphology.
Ideally, a good sperm ( Sperm
Video ) should have a regular oval head, with a
connecting mid-piece and a long straight tail. If too
many sperms are abnormally shaped (this is called teratozoospermia,
when the majority of sperm have abnormalities such as
round heads; pin heads; very large heads; double heads;
absent tails) this may mean the sperm are functionally
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 even upto 85% abnormal forms is considered to
be acceptable !)
Sperm clumping or agglutination.
Under the microscope, this is seen as the sperms sticking
together to one another in bunches. This impairs sperm
motility and prevents the sperms from swimming upto
through the cervix towards the egg.
Putting it all together, one looks for
the total number of "good" sperms 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.
What
does the presence of pus cells in the semen signify
?
Whether pus cells are present or
not. While a few white blood cells in the semen
is normal, many pus cells suggests the presence of seminal
infection. Unfortunately, many labs cannot differentiate
between sperm precursor cells ( which are normally found
in the semen) and pus cells. This often means that men
are overtreated with antibiotics for a "sperm
infection" which does not really exist !
Some labs use a computer to do the semen
analysis. This is called CASA, or 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 lab.
What does a normal
semen analysis report mean ?
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 fertilisation)!
What
are the reasons for a poor semen analysis report ?
Poor sperm tests can results 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)
If the 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.
Azoospermia
Some men will find to their dismay that
they have a zero sperm count. This is called azoospermia,
and comes as a complete shock, as these men have normal
libido, can ejaculate normally, and their semen looks
normal .
If the report shows your sperm count
is zero, please ask the laboratory to re-check it again.
It's useful to request the laboratory to check two consecutive
semen samples, ejaculated about 1 hour apart ( sequential
semen analysis). The laboratory should be also requested
to centrifuge the sample and check the pellet for sperm
precursors. Some men will have occasional sperm in the
pellet, which means they are not really azoospermic.
This is called cryptozoospermia.
If the report is persistently zero, then the next step
is to find out what the reason for the azoospermia is.
There are 2 possibilities - obstructive azoospermia;
or non-obstructive azoospermia. Men with obstructive
azoospermia have normal testes which produce sperm normally,
but whose passageway is blocked. This is usually a
block at the level of the epididymis, and in these
men the semen volume is normal; fructose is present;
the pH is alkaline; and no sperm precursor cells are
seen on semen analysis. On clinical examination, they
typically have normal sized firm testes, but the epididymis
is full and turgid.
Some men have obstructive azoospermia
because of an absent vas deferens. Their semen volume
is low ( 0.5 ml or less); the pH is acidic and the fructose
is negative. The diagnosis can be confirmed by clinical
examination, which shows the vas is absent. If the vas
can be felt in these men, then the diagnosis is a seminal
vesicle obstruction.
Men with non-obstructive azoospermia
have a normal passageway, but abnormal testicular function,
and their testes do not produce sperm normally. Some
of these men may have small testes on clinical examination.
The testicular failure may be partial, which means that
only a few areas of the testes produce sperm, but this
sperm production is not enough for it to be ejaculated.
Other men may have complete testicular failure, which
means there is no sperm production at all in the entire
testes. The only way to differentiate between complete
and partial testicular failure is by doing multiple
testicular micro-biopsies to sample different areas
of the testes and send them for pathological examination.
What if the sperm count is persistently
low ? Then other tests may be advised, to try to pinpoint
what the problem is; and these are described in the
next chapter.
Next page: Beyond
the Semen Analysis
Previous page:
Testing the
Man - Semen Analysis (Page 1)
Table of Contents
|
