To investigate to see if there is a problem with your fertility. This is often performed if you are in a heterosexual relationship and your partner is having trouble becoming pregnant.
It is also necessary after a vasectomy operation to ensure that the sterilisation operation was successful and that you are no longer fertile. This test is called a post-vasectomy semen analysis (PVSA).
Semen analysis - When you think you might have a fertility problem. This is usually undertaken one year after trying to conceive with natural intercourse.
Post-vasectomy semen analysis – 12 weeks after the vasectomy with at least 20 ejaculations since the operation.
A semen sample collected in a sterile container provided by the laboratory or doctor. It is important that the specimen container has been tested to ensure it is not toxic to sperm.
In order for the test to be reliable, you may need to abstain from masturbation or sex for two to seven days before the sample is collected. You should follow the instructions given to you by the laboratory or your doctor.
Semen analysis is used to determine whether a man might be infertile (unable to get a woman pregnant). The semen analysis looks at many aspects of the semen and sperm. Semen analysis to determine fertility should be performed on a minimum of two samples at 3 months apart, because sperm count and semen consistency may vary from day to day and some conditions, e.g. the common cold, can temporarily affect sperm levels.
The semen analysis can also be used to count sperm after a man has a vasectomy. If there are still sperm present in the semen, the man and his partner will have to take precautions so that his partner will not become pregnant. He will have to return for one or more sperm counts until the sperm are cleared from his sample(s).
There are two main reasons for semen analysis.
Following vasectomy: Semen analysis is recommended following a vasectomy to make sure that the sterilisation operation has been successful.
Testing for infertility: Semen analysis is performed when your doctor thinks that you might have a fertility problem. About one in six couples experience problems conceiving. Male infertility is on the increase and male factors are implicated about 50% of the time. Male infertility has many causes and some of these can be treated successfully. If male factors are the cause, analysis of the semen is necessary to determine what is preventing fertility and to evaluate whether assisted reproductive technology (e.g. IVF) would be helpful. If sperm are suboptimal, a form of IVF called ICSI (intracytoplasmic sperm injection) can be used, whereby a single sperm is carefully injected directly into the woman’s egg to cause fertilisation. When a semen analysis is abnormal, your doctor may ask for one or more repeat tests.
The typical volume of semen collected is around a half to one teaspoonful (1.4 millilitres) of fluid. Less semen might indicate a possible blockage or retrograde (backwards) ejaculation. The semen should initially be thick and then become thinner within thirty minutes. If this does not occur, the viscosity may reduce sperm movement.
Sperm concentration is measured in millions of sperm per millilitre of semen. The normal count is 16 million sperm or more per millilitre. Fewer sperm and/or a lower sperm concentration may reduce fertility and therefore the chance of pregnancy. Following vasectomy, the goal is to have no sperm detected in the semen sample.
The percentage of moving sperm in a sample is known as its 'motility'. The rate and direction of travel of the sperm is also assessed. At least 30% of sperm should be progressively motile up to one hour after ejaculation. The progression of the sperm is rated from 1 to 4 with 3-4 indicating good motility. If less than half the sperm are motile, a stain is used to identify dead sperm. This is called a 'sperm vitality test'.
Morphology analysis is the study of the size, shape, and appearance of the sperm cells. The analysis evaluates the structure of 400 sperm, and any defects are noted. The more abnormal sperm that are present, the lower the likelihood of fertility.
Semen pH should be between 7.2 and 7.8, fructose between 150-600 mg/dL, and there should be fewer than 1 million white cells per mL.
Common causes of male infertility include reduced testicular function (failure of the testicles to produce enough sperm) and obstruction of the tubes that carry semen to the penis.
When a doctor is evaluating a man's fertility, each aspect of the semen analysis is considered, as well as the findings as a whole. Each part of the semen analysis either contributes to fertility or lessens it, but the results do not necessarily predict the eventual outcome. Couples with poor results may still conceive, with or without assistance, and those with apparently good results may experience difficulties.
Several factors can affect the sperm count and other semen analysis values. A man may have a lower sperm count if he has damage to the testicles, has gone through radiation treatment of his testicles, or has had exposure to certain drugs (such as azathioprine, cimetidine, and some cancer chemotherapy drugs). A man with a higher level of oestrogens may have a lower sperm count.
When a couple cannot become pregnant, it is much easier, less invasive, and less expensive for the man to be tested first. A man requires only semen analysis, and the samples can be collected and a male cause of infertility confirmed or ruled out very quickly. If the man’s semen is normal, then it makes sense to move ahead with the more invasive and expensive tests for female infertility.