The fractional postcoital test: a reappraisal

Postcoital tests (PCTs) were conducted following artificial insemination with either live or dead spermatozoa. The cervical mucus samples were analyzed for sperm counts and acid phosphatase activity. The results indicate that the final distribution of mucus and sperm in the PCT sampling catheter is not truly representative of their original distribution within the cervix. Moreover, PCTs done after insemination with semen containing only dead sperm yield unrealistically high sperm counts and high cervical mucus acid phosphatase levels. This is apparently due to the translocation of semen from the area of the external os into the mucus sample by the sampling catheter. This problem can be largely prevented by removing a plug of mucus from the external os prior to the catheter sampling procedure.