Cervical factors for infertility
The cervix is the opening between the vagina and the uterus.
Cervix is lined by cervical glands, these glands produce mucus.
Once sperm are ejaculated they swim through this mucus from the vagina through the cervix and into the uterus. The mucus also provides nourishment for the sperm. If the cervical mucus is inadequate, the sperm cannot reach and fertilize the egg.
Estrogen stimulates the production of cervical mucus and low levels of this hormone can lead to diminished or thickened cervical mucus which inhibits sperm transport.
How cervix can be the cause for infertility:
Consistency of cervical mucus plays major role in sperm transport. Thin cervical mucus can assist sperms to swim up inside the uterus after intercourse and Thick or less cervical mucus will hamper the sperm movements.
In fertile period when the follicle has ruptured and egg is released cervical mucus present in the cervix is thin slimy and in more quantity, so if intercourse takes place the semen deposited on cervix, sperms directly can swim up inside uterus.
Some drugs given for fertility treatment can deteriorate the cervical mucus quality, making cervical mucus thick and hostile for sperms.
Infection at the cervix also may cause bad quality of cervical mucus.
Sometimes cervical mucus may have anti sperm antibodies. These anti sperm antibodies sense the sperms as foreign body and destroy them, either by formation of large clumps-agglutination or make them immobile.
Anatomical defects/growths at the level of cervix may be responsible for the mechanical obstruction for the sperms to swim up inside uterus.