The P-C (post-coital) test, also known as the Huhner test or Sims test, is one that helps determine what happens to sperm after intercourse.

In the vagina, a large number of sperm normally lose their activity because the secretions of the vagina are usually acidic and not favorable to sperm.

On the other hand, the cervix has secretions which are alkaline and very thin near the ovulation portion of the menstrual cycle. These secretions are favorable and permit sperm to swim through the cervix into the uterus. The uterine secretions are also favorable to sperm as they migrate from there into the tubes.

Sperm can remain active in the tubes for at least a week, sometimes longer. We know that under certain circumstances sperm can remain active in the cervical mucus for as long as a week, but during the average menstrual cycle they do not ordinarily remain motile in the cervix for more than about three days.

For the post-coital test, intercourse should be timed approximately between 8 to 15 hours before your appointment. Having intercourse more than 15 hours before your appointment may still yield a satisfactory test, but if the test is poor you would be asked to come in sooner the next time. Having intercourse less than 8 hours before your appointment may also yield a satisfactory test, but we prefer to see how the sperm survive after a longer interval.

If intercourse cannot be performed within this time period, do not get overly concerned. Simply call and cancel your appointment and try again at the next most favorable time. You can phone any time between 9:00 and 10:00 A.M., Monday-Friday and tell the receptionist you are coming in for a post-coital test that day.

There are no specific instructions as to techniques of intercourse, etc. for the test because the primary aim of the test is to determine what ordinarily is happening.

Many women complain to us that after intercourse they lose most of the semen and worry that perhaps no sperm is being retained. Ordinarily a substantial amount of fluid is lost after intercourse, but this is a mixture of both the female secretions and semen.

It is not necessary to change any customary habits regarding intercourse simply because the test is scheduled, with the following exceptions. If you have been in the habit of using lubrication prior to intercourse or you have been in the habit of douching following intercourse, please avoid these practices for the post-coital test. Indeed, these practices should not be done any time around ovulation in couples who are trying to conceive.