The interpretation and significance of the fractional postcoital test.

The investigation was designed to objectively determine the clinical usefulness of the fractional postcoital test. Forty-three normal subjects had midcycle cervical mucus collection at various times after insemination. There was a significant correlation between the number of motile sperm at the internal os level and the total sperm count within the cervical mucus. The median internal os count was 15 motile sperm per high-power field with a lower 95% confidence limit of five motile sperm per high-power field. Therefore, the fractional postcoital test is useful clinically as it is a physiologic indication of sperm transport in cervical mucus.