semen analysis measures the amount of semen a man
produces and determines the number and quality of
sperm in the semen sample.
analysis is usually one of the first tests done to help determine whether a man
has a problem fathering a child (infertility). A
problem with the semen or sperm affects more than one-third of the couples who
are unable to have children (infertile).
Tests that may be done
during a semen analysis include:
- Volume. This is a measure of how much semen is
present in one ejaculation.
- Liquefaction time. Semen is a thick gel at the
time of ejaculation and normally becomes liquid within 20 minutes after
ejaculation. Liquefaction time is a measure of the time it takes for the semen
- Sperm count. This is a count of the number of
sperm present per
milliliter (mL) of semen in one ejaculation.
- Sperm morphology. This is a measure of the
percentage of sperm that have a normal shape.
- Sperm motility. This is a measure of the
percentage of sperm that can move forward normally. The number of sperm that
show normal forward movement in a certain amount of semen can also be measured
- pH. This is a measure of the acidity (low
pH) or alkalinity (high pH) of the semen.
- White blood cell count. White blood cells are not
normally present in semen.
- Fructose level. This is a measure of the amount of
a sugar called fructose in the semen. The fructose provides energy for the
Why It Is Done
A semen analysis is done to determine
- A man has a reproductive problem that is
vasectomy has been successful.
reversal of a vasectomy has been successful.
How To Prepare
You may be asked to avoid any sexual
activity that results in ejaculation for 2 to 5 days before a semen analysis.
This helps ensure that your sperm count will be at its highest, and it improves
the reliability of the test. If possible, do not avoid sexual activity for more
than 1 to 2 weeks before this test, because a long period of sexual inactivity
can result in less active sperm.
You may be asked to avoid
drinking alcohol for a few days before the test.
Be sure to tell
your doctor about any medicines or herbal supplements you are
How It Is Done
You will need to produce a semen sample,
usually by ejaculating into a clean sample cup. You can do this in a private
room or in a bathroom at your doctor's office or clinic. If you
live close to your doctor's office or clinic, you may be able to
collect the semen sample at home and then transport it to the office or clinic
- The most common way to collect semen is by
masturbation, directing the semen into a clean sample cup. Do not use a
- You can collect a semen sample during sex by withdrawing
your penis from your partner just before ejaculating (coitus interruptus). You
then ejaculate into a clean sample cup. This method can be used after a
vasectomy to test for the presence of sperm, but other methods will likely be
recommended if you are testing for infertility.
- You can also
collect a semen sample during sex by using a condom. If you use a regular
condom, you will need to wash it thoroughly before using it to remove any
powder or lubricant on it that might kill sperm. You may also be given a
special condom that does not contain any substance that kills sperm
(spermicide). After you have ejaculated, carefully remove the condom from your
penis. Tie a knot in the open end of the condom and place it in a container
that can be sealed in case the condom leaks or breaks.