Naturally, the cervical mucus and the female reproductive tract are at an acid pH between 4.5 and 5. This pH limits the survival of spermatozoa, which can only survive for about 72 hours.
This mechanism of action sets limits so that the sperm that fertilize the ovum are always freshly ejaculated and that fertilization does not occur by an old sperm that has been in the uterine cavities for too long.
However, in certain conditions where the mucus is too acidic, below 4.5, the sperm do not manage to survive the passage through this cervical mucus.
This prevents them from passing into the uterine cavity and fertilizing the egg. In these cases, when this alteration is detected, the couple can undergo artificial insemination treatment to place the sperm in the uterine cavity. In this way, the passage of the sperm through the altered mucus is prevented.