This is one of the oldest tests in investigating infertility and has been done for well over 100 years. It's quite an obsolete test and few doctors do it anymore, because it provides such limited information
The post coital test (PCT)
Timing the PCT is critical, and it must be done in the preovulatory period when the cervical mucus is profuse and clear. If you are using an ovulation predictor kit, this kit will be the determining factor as to when you will have intercourse. Remember, to have sex that morning, and do not use any lubricants, douche - or bathe (a shower is acceptable) and be sure and contact your physician to schedule a time to come in after intercourse.
The gynecologist examines a small sample of the cervical mucus under a microscope some hours after sexual intercourse. As you can imagine, it's no fun having to drag yourself from your warm bed where you've just enjoyed making love, to the clinic to allow the gynecologist to examine your insides! This is why most women dislike this test intensely.
- The mucus is sucked painlessly from the cervical canal during an internal examination
- Most doctors feel that the best time to do this is about 6 to 12 hours after sex, but this timing is not critical
- The test is said to be positive if much normal live sperm are seen swimming in the mucus sample
- The sperm should be swimming in a fairly straight line and reasonably vigorously
A positive PCT is very reassuring and implies that :
- The husband is likely to be producing enough normal sperm
- Intercourse results in semen being deposited in the vagina
- The cervical glands are healthy
- Sufficient estrogen is being produced before ovulation, suggesting that ovulation is normal
- There are no antibodies in the mucus hostile to the sperm
What if the PCT is negative?
Some of the reasons for a negative test is:
- The PCT was not done at the best time. For example, the PCT may have been done too early or too late in the cycle. Wrong timing is the commonest reason for a negative test and can even cause repeated negative tests.
- There was no ovulation the month of the test - perhaps because of the strain or stress of making love to order.
- The sperm count was poor. Obviously, men with persistently low sperm counts, or men with poor motile sperm, may be responsible for a negative PCT.
- There may be an abnormality of the cervix - for example, chronic infection in the cervix may prevent the production of adequate mucus; and some women with a scarred cervix may not produce enough mucus
- Patients who have had surgery on the cervix ( for example, cervical conization, in which a cone of cervical tissue is removed to treat cervical dysplasia) often have this problem.
- The cervix is producing antibodies to the sperm.
- Medications such as clomiphene, tamoxifen, progesterone, and danazol - all drugs used for infertility problems - can interfere with the production of good mucus.
Remember that a negative test is meaningful only if it is repeatedly negative under perfect conditions. We never do the PCT test in our practice, because we feel it provides very limited information and does not affect the treatment plan.