Definition - What does Cervical Os mean?
The cervical os is the small hole at the center of the cervix. The cervix serves as the opening between the vagina and the uterus and changes in position and function throughout the menstrual cycle.
The movement of the cervix and the opening and closing of the os allows the inward passage of sperm during ovulation and allows the outward passage of menstrual blood during menstruation. The os also opens, or dilates, during childbirth.
FertilitySmarts explains Cervical Os
Throughout a woman’s monthly menstrual cycle, the cervical os opens and closes in collaboration with the cervical position. Cervical position, the angle and direction the cervix is facing, changes through the menstrual cycle, in conjunction with phases of menstruation, ovulation, and non-fertile times.
The feel and position of the cervix, along with any fluid present, can help to indicate the current phase of fertility. Recognizing naturally fertile and non-fertile periods is an effective fertility awareness method (FAM), which, when practiced, can help increase the chances of conception through intercourse.
Women can access the cervical os during a simple self-examination. With clean, washed hands, two fingers are inserted into the vagina, feeling for the cervix in the back of the vaginal space. The cervix will feel round, and the os resembles a small donut with a hole in the center. It may be easier to access the cervix by elevating one leg or squatting.
When a woman is fertile, or ovulating, her cervix will be high, near the top of the vagina, and the cervical os will be open to allow sperm to enter. The surrounding cervix will be soft, similar to pursed lips. Cervical mucus, or vaginal discharge, will be present. When a woman is not fertile, her cervical position will be low. The os will have closed, and the surrounding cervix will feel firm, like the cartilage on the tip of a nose. During menstruation, the os will open to allow the flow of menstrual blood.