The aim of a post coital test is to evaluate sperm survival in the cervical mucus and to determine the concentration of progressively motile spermatozoa. It is performed in order to investigate the cervical factor or the presence of anti-sperm antibodies (ASA) as the underlying cause of infertility for a couple.
In order to receive accurate results, the test must be performed before ovulation but as close as possible to it. The reason is that around the time of ovulation, cervical mucus becomes more permeable for spermatozoa. The time of ovulation is determined by clinical criteria, usually by an ultrasound examination known as folliculometry. It is also very important that the mucus is evaluated in the laboratory at a standard time—between 9 and 14 hours after sexual intercourse.
Instructions for the couple
In preparation for the postcoital test, the couples should be informed of the most suitable day for the test, and be instructed:
– to abstain from intercourse, and the man from masturbation, for 2 days before the test
– to have vaginal intercourse the night before the test date
– to not use any vaginal lubricants during intercourse and the woman should not douche after intercourse (taking a shower, but not a full bath, is permitted)
– that the woman should report to the clinic for the test the following morning.
Results and interpretation
The test is negative if no spermatozoa are found in the mucus.
The presence of any spermatozoa with progressive motility in endocervical mucus 9–14 hours after intercourse argues against significant cervical factors, and sperm autoimmunity in the male or female, as possible causes of infertility.
When NP spermatozoa exhibiting a shaking phenomenon are seen, there may be sperm antibodies either in the mucus or on the spermatozoa.