All about the cervix

IT’S a body part you probably only think about during pregnancy, when the speed of its dilation signifies how soon your baby will enter the world. But the cervix, its position, and other variants, can tell a lot —including about your health status and ability to perform certain functions.

The medical definition of the cervix is the lower, narrow part of the uterus (womb). The cervix — which is about 3-5 centimeters long — forms a canal that opens into the vagina, which leads to the outside of the body.

What’s its purpose? It depends on what state a woman is in. According to medical literature, the cervix acts as the door to the uterus which sperm can travel through to fertilise eggs. When a woman is not carrying a child, it helps keep foreign objects out of her body. When she’s pregnant, the cervix helps keep the baby in place until it is fully developed.

The shape and colour of the cervix varies slightly throughout a woman’s menstrual and life cycles. You can tell a lot about your fertility, cycle and health by the texture and position of your cervix.

Fertility

The consistency of your cervical mucus is a great indicator of when you are most fertile. Before ovulation, you will notice a sticky, cloudy looking mucus which usually turns into a clear and slippery secretion. You are considered most fertile when the mucus is clear, thick and slippery. When ovulation time is near, it tends to be watery so the sperm can penetrate through the cervical mucus.

Cervical mucus functions in sperm transport and protection during the fertile window to increase the chances of fertility, and when it malfunctions it then decreases fertility potential and may be a major cause of infertility in some couples who have been trying to conceive.

Position

When your cervix is high, soft and open, you are getting closer to ovulation. Your cervical mucus will also change and transform into a more raw egg white consistency.

A low cervix is a term used to describe a cervix that is felt low in the vagina, sometimes at the opening of the vagina, or even outside of the vagina in severe cases of uterine prolapse. This occurs when the pelvic floor muscles are overstretched and damaged, more commonly during childbirth. The risk for this increases with the delivery of big babies, forceps delivery, vacuum delivery, prolonged second stage of labour with excessive pushing to deliver the head of the baby, and precipitous labour with an extremely short period of pushing and rapid delivery of the foetus.

A low cervix is sometimes used to describe a weak cervix as occurs in cervical incompetence where the muscles of the internal cervical opening have become weak and damaged. This may occur if a part of the cervix is removed because of precancerous changes in the cervix, repeated termination of pregnancy, and dilatation of the cervix for other medical reasons.

Length

Before pregnancy, the cervix is closed, long and firm. As the body gets ready for labour, the cervix decreases in length, and finally opens as the woman prepares to give birth.

If an ultrasound shows that the cervical length is less than 29 millimeters but greater than 25 millimeters, the health care provider might recommend more frequent ultrasounds to monitor cervical length. If the cervical length is less than 25 millimeters (short cervix) before 24 weeks of pregnancy and the woman is only carrying one baby, the health care provider might consider a stitch — cervical cerclage, the Mayo Clinic explains.

Incompetence

Recurrent miscarriages can be a result of cervical incompetence or weakness.

During normal pregnancy, the cervix remains closed and maintains the pregnancy until labour approaches around 37 weeks gestation.

During labour, the cervix gradually shortens and dilates. At this point, with additional contractions of the uterus, the baby is delivered. Recurrent miscarriages occur when the cervix is unable to maintain its structural integrity and this results in it prematurely dilating and shortening, resulting in loss of the pregnancy.

Risk factors include three or more miscarriages; previous surgery to the cervix such as a cone biopsy, which is treatment of precancerous cells of the cervix; congenital malformations of the uterus; and multiple pregnancies.

Unfortunately, there is no pre-pregnancy test to determine if the cervix is incompetent; however, most of the time the diagnosis is made after a history of recurrent miscarriages or in miscarriages in patients with previous cervical surgery.