The post-coital test assesses the quality of the cervical mucus and sperm survival following intercourse right before ovulation. While inaccurate and controversial, this test is useful in detecting major sperm and mucus abnormalities, as well as abnormalities of sperm-mucus interactions.

The test involves examining a specimen of cervical mucus, obtained four to eight hours after intercourse, under the microscope. One should expect at least three to five forward-moving sperm per high-power field, as well as thin, watery, stretchy mucus.

The test lasts several seconds and is not painful. Results are given  immediately to the patient. The test is perform one day after the ovulation predictor kit indicates a positive change.