The length of the cervix affects whether the mother will give birth prematurely

What is the normal cervical length during pregnancy?

The cervix or cervix is the part that connects the uterus and vagina. This cervical length can change with your gestational age. The cervix is closed during pregnancy until before you give birth. As the time of birth approaches, the cervix will open up to be used as a way out for the baby.

Normal cervical length is 4-5 cm when you are not pregnant. Meanwhile, when you are pregnant, the length of the cervix is getting smaller. Normal cervical length during pregnancy, namely:

At 16-20 weeks of gestation it is 4-4.5 cm
At 24-28 weeks of gestation it is 3.5-4 cm
At 32-36 weeks of gestation it is 3-3.5 cm

It can be seen that the shorter the length of the cervix can mean that the gestational age is getting older and the time of birth is getting closer. However, if the length of the cervix becomes shorter and does not match the gestational age, this can mean a risk of preterm birth.

The length of the cervix can determine whether a woman will give birth prematurely

Many studies have shown that the shorter the cervix (which is not according to gestational age), the greater the risk of preterm birth. One study revealed that the average length of the cervix is 3.5 cm at 24 weeks' gestation. When the length of the cervix at this gestational age is less than 2.2 cm, the possibility of a pregnant woman giving birth prematurely is 20%.

Research published in the American Journal of Obstetrics and Gynecology in 2002 also proved that cervical length less than 3 cm before 16 weeks of gestation is associated with preterm birth.

Based on these two studies, it can be concluded that the length of the cervix which shortens rapidly can increase the risk of preterm birth. Cervical length at 20-24 weeks gestation is the best predictor of preterm birth.

To find out the length of the cervix, it is recommended that you do a cervical scan. Usually done at about 20 weeks of gestation. This you need to do, especially if you have had a miscarriage in a previous pregnancy, your baby was premature in a previous pregnancy, or you have had cervical surgery.

What affects the length of the cervix?

Before pregnancy, the cervix is usually closed and stiff. Meanwhile, during pregnancy the cervix will undergo many changes. The cervix will gradually soften, shorten, and begin to open as your fetus grows in the womb.

If the length of the cervix gets shorter, this is a sign that your baby will be born. However, if this happens faster than normal, then you can give birth prematurely. This may vary between pregnant women.

The various factors that affect the length of the cervix during pregnancy are:

Biological differences between pregnant women
The uterus is stretched too large (overdistention)
Complications caused by bleeding during pregnancy
Infection
Inflammation of the lining of the uterus
Cervical incompetence, occurs when cervical tissue weakens, increasing the risk of preterm birth