How to measure cervical length

The female uterus is a very important organ for women. The part where the female uterus connects to the vagina is called the cervix. Many women may suffer from cervicitis, and the health of the cervix is ​​also related to the future childbirth of women. Therefore, women should have a good examination of these parts of the body before pregnancy. So how is the length of the cervix measured?

The uterus can be divided into two parts: the cervix and the uterine body. After pregnancy, the uterine body gradually expands as the fetus grows, from the size of a fist before pregnancy to the size of a basketball at full term. The cervix begins to soften and thin in late pregnancy and at full term, and begins to dilate during labor, allowing the fetus to pass through the cervix and be delivered vaginally. There is a close relationship between cervical length and premature birth. Regardless of the cause and mechanism of premature birth, the cervix will change before premature birth actually occurs. In the past, doctors could only use internal examination to check the length of the cervix. In recent years, ultrasound has become popular. Doctors can also use abdominal ultrasound or vaginal ultrasound to check the length of the cervix, which plays a big role in predicting the chance of premature birth and deciding whether to conduct further examination and treatment.

1. Pregnant women need to have their cervical length measured.

The cervical length test is mainly used to screen pregnant women at high risk of premature birth and late miscarriage. Of course, if hospital conditions permit, every pregnant woman can be screened, especially first-time pregnant women, as sometimes it is not known whether there are some factors for premature birth. Moreover, the incidence of premature birth is about 5-12%, so screening is necessary. Ultrasound screening is economical, convenient, and allows for repeated follow-up in China. The focus is on screening people at high risk of premature birth, including:

1. Those with a history of late miscarriage and/or premature birth: Pregnant women with a history of premature birth have a risk of recurring premature birth that is twice that of ordinary pregnant women. The younger the gestational age of the previous premature birth, the higher the risk of another premature birth. If a previous twin pregnancy had a preterm birth before 30 weeks, there is also a higher risk of preterm birth even if the current pregnancy is a singleton.

2. Vaginal ultrasound examination: Pregnant women whose cervical length (CL) is ≤25mm during mid-pregnancy vaginal ultrasound examination.

3. Those with a history of cervical surgery: The risk of premature birth increases after treatment with cervical conization or loop electrode excision procedure (LEEP), and the risk of premature birth also increases in those with uterine developmental abnormalities.

4. Multiple pregnancies: The premature birth rate of twins is nearly 50%, and the premature birth rate of triplets is as high as 90%.

5. Those who use assisted reproductive technology to conceive: Those who use assisted reproductive technology to conceive have a higher risk of premature birth.

6. Pregnant women may have pregnancy complications, fetal abnormalities, and an increased risk of premature birth.

Cervical length examination mainly predicts spontaneous preterm birth and late miscarriage.