The cervix is an extension of the lower uterus which protrudes into the vaginal vault. As such, it serves as the gateway into the uterine cavity from the vagina. Sperm ejaculated in the vagina during sexual intercourse must traverse the cervix before entering the uterus. The cervix is lined with glandular tissue which secretes cervical mucus responsible for facilitating the passage of sperm through the cervix. Therefore, abnormalities in the cervix or cervical glands may impede the entry of sperm into the uterus and contribute to infertility.
Cervical factor may occur secondary to the intake of certain medications, cervical or uterine surgery, congenital anomalies, and unexplained factors. Diagnosing cervical factor infertility begins with a comprehensive medical history, which can often determine whether risk factors for cervical factor exist. In the recent past, testing for cervical factor used to include the post coital test, which assessed the behavior of sperm within cervical mucus. Inaccuracies and inconsistencies in the post coital test led to the abandonment of such testing. Today, assessing cervical factor is performed using transvaginal ultrasonography and mock embryo transfers, which can often reveal whether a significant abnormality exists within the cervix.
Treatment for mild cervical factor often involves intrauterine insemination (IUI/artificial insemination) of sperm. This simple technique facilitates the passage of sperm into the uterine cavity by bypassing the cervix and depositing sperm through the cervix directly into the top of the uterine cavity. Severe cervical factor infertility (severe cervical stenosis/stricture, absent cervix) can often be treated with in vitro fertilization and laparoscopic GIFT or ZIFT.