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Home > Health Library > Semen Analysis
A semen analysis is a test to measure the number and quality of sperm. The lab will also measure the amount of liquid (semen) produced with the sperm.
This test is usually one of the first tests done to help find the cause of sperm-related infertility problems.
Tests that may be done during a semen analysis include:
This is a measure of how much semen is present in one ejaculation.
Semen is a thick gel at the time of ejaculation. It normally becomes liquid within 20 minutes after ejaculation. Liquefaction time is the time it takes for the semen to turn to liquid.
This counts the number of sperm present per milliliter (mL) of semen in one ejaculation.
This is a measure of the percentage of sperm that have a normal shape.
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. This is called motile density.
This is a measure of the acidity (low pH) or alkalinity (high pH) of the semen.
White blood cells are not usually present in semen.
A semen analysis is done to find out if:
You may be asked to avoid any sexual activity that results in ejaculation for 2 to 5 days before this test. This helps to make sure that your sperm count will be at its highest. It also makes the test more reliable. If possible, do not avoid sexual activity for more than 1 week before this test. A long time without sexual activity may 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 take.
You will need to produce a semen sample. A semen sample is often collected by masturbation. 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.
Since semen samples may vary from day to day, two or three different samples may be checked within a 3-month period. This helps to get accurate testing.
A semen analysis to test how well a vasectomy has worked is usually done 12 weeks after the vasectomy.
Getting a semen sample does not cause any discomfort.
There are no known risks from having this test.
Results of a semen analysis are often ready within a day.
If problems are found, more testing may be done. Other tests may include measuring hormones, such as testosterone, luteinizing hormone (LH), follicle-stimulating hormone (FSH), or prolactin. A small sample (biopsy) of the testicles may need to be checked if the sperm count or motility is extremely low.
Current as of:
February 11, 2021
Author: Healthwise StaffMedical Review: Sarah Marshall MD - Family MedicineAdam Husney MD - Family MedicineKathleen Romito MD - Family MedicineFemi Olatunbosun MB, FRCSC - Obstetrics and Gynecology
Current as of: February 11, 2021
Author: Healthwise Staff
Medical Review:Sarah Marshall MD - Family Medicine & Adam Husney MD - Family Medicine & Kathleen Romito MD - Family Medicine & Femi Olatunbosun MB, FRCSC - Obstetrics and Gynecology
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