by Andre Denis, MD and Dr. Andre L.C. Denis
There are multiple causes of infertility. The three biggest individual causes are abnormalities of ovulation, abnormalities of the fallopian tubes, and factors that arise from the male ("male factor infertility"). These 3 factors account for about 80% of all cases of infertility. The male alone is the cause in 20-35% of cases of infertility. An evaluation of the male should be one of the very first tests carried out in the investigation of the infertile couple.
Sometimes, a man's medical history is suggestive of a potential male factor. Some men may have a history of sexual dysfunction or abnormal ejaculation. Alternatively, others may have had previous surgeries or injuries that may lead to problems in semen production. We find it extremely important to review the medical history of the male partner of an infertile couple.
The initial diagnostic study that most men have is the semen analysis. The semen analysis is one of the few tests which have withstood the test of time and which continue to be considered an integral and important part of the evaluation of the couple. The analysis is generally performed on a specimen that has been produced by means of masturbation into a sterile container.
For those men who are unable or unwilling to masturbate, special semen collection devices, which are used like condoms during intercourse, can also be used to collect sperm for analysis. Ideally the male should abstain from ejaculation for 2-7 days prior to the analysis. The specimen should be evaluated within one hour after collection.
The analysis consists of an evaluation of a number of factors. Basic measurements include the volume of semen ejaculated (in milliliters), the concentration of sperm within the ejaculate (usually expressed in number of sperm per milliliter of semen), the percentage of the sperm which are moving (motility), and the quality of the movement (wiggling, swimming in circles, swimming in straight lines), known as the progression.
Labs may also report other values such as the pH, viscosity, color of the semen, the viability (percentage of sperm which are alive and dead) and other parameters. Some laboratories will also analyze sperm with computer guided systems (CASA or Computer Assisted Semen Analysis).
Through tracking of each individual sperm, these analyses can provide extremely detailed data such as the speed of movement, the lateral head displacement of the sperm (how much "wiggling" there is) and other parameters. Although CASA has a role in research, it is not necessary for routine evaluations.
Another frequently performed test for males is the post-coital test (PCT), also called the Sims-Huhner test. The test consists of asking the couple to have intercourse during the middle of the woman's menstrual cycle and 2-12 hours later have the female come into the office for an exam.
At the time of the exam, which is done in the same fashion as a routine pap smear, some of the mucus present is examined under the microscope. In a normal test, sperm should be visible and swimming normally. This test is most useful when it is normal, which implies that enough sperm are available for fertilization to take place.
Unfortunately an abnormal result can be misleading. Many factors such as poor timing, low-grade vaginitis (inflammation of the vagina), etc. can make the test seem abnormal although the couple could still potentially achieve pregnancy. Given its simplicity and safety, however, we still frequently use this test to rule out a possible male factor.