The postcoital test examines the mucus sample collected from the cervix a few hours after unprotected sexual intercourse. It is performed during ovulation, when the mucus has optimal properties enabling penetration of sperm to the uterus. The mucus is microscopically examined immediately after sample collection. Under normal circumstances, motile sperms should be present in the mucus. The absence of motile sperms in the sample may indicate a problem either on the part of the female partner (unsuitable composition of the mucus) or on the part of the male partner (inadequate sperm motility). However, it may also indicate just an incorrect timing of the examination or insufficient sample of the mucus.