Post coital literally means “after intercourse” which is when this fertility test is conducted. The patient has intercourse at home usually between cycle days 12 and 15 (or a day around the LH surge as measured by urinary ovulation predictor kits). Afterwards, the female comes to the office and a sample of the cervical mucus is taken for microscopic examination.
The post coital fertility test (PCT) allows for evaluation of sperm in the cervical mucus and to determine the consistency of the mucus. Sperm must swim through the cervical mucus from the vagina, through the cervix, and into the uterus. Normal sperm will be active and swim in approximate straight lines through the mucus. If the mucus is too thick, sperm impedance can be observed.
Although theoretically this test should be useful, research has shown that the post coital fertility test is usually not necessary. The post coital test has not be shown to be a reliable predictor of subsequent fertility.
In addition, by the time a post coital test is indicated, it is usually best for the patient to proceed with treatment such as IUI. This common and frequently successful treatment is performed by placing specially prepared sperm directly into the uterus, thus bypassing the cervix. The IUI procedure must be performed by trained medical personnel as unwashed sperm can lead to severe cramping and potentially fatal allergic reactions.
Regretfully, the post coital test is a poor predictor of successful IUI treatment and thus this test has largely been abandoned.