During intercourse, sperm are ejaculated into the vagina and must travel through the vaginal canal, past the cervix and into the uterine cavity to the fallopian tubes. The cervical glands produce mucus that nourishes and serves as a transport medium for sperm. If the mucus is too thick or absent, it can impede the progress of the sperm.
Sometimes a woman will produce antibodies to her partner’s sperm. This means that her immune system mistakenly identifies sperm as an invading pathogen (like a virus or bacteria) and produces antibodies to destroy it. The post coital (after intercourse) test is used to diagnose cervical factor infertility by some physicians.
A sample of the cervical mucus is taken from the vagina, after intercourse, and examined under the microscope. Numerous dead or non-motile sperm indicate a cervical mucus problem. Furthermore, it is possible that a woman will have no cervical mucous because of past surgery to the cervix (such as cone biopsy for abnormal Pap Smears).
The cervical canal may then be narrowed (stenosis). Many reproductive endocrinologists do not perform the post coital test because most treatments offered (such as IUI and IVF) bypass the cervix and cervical mucous.
Intrauterine insemination (IUI) is often the first line treatment for cervical factor infertility. In IUI, the partner’s specially washed, prepared, and concentrated sperm are inserted directly into the uterus using a catheter. This process bypasses the cervix and is often successful.