How do you measure the length of the neck?

The normal range of cervical length varies according to the gestational age. 1. Looking for cervical length data On the B-ultrasound sheet, cervical length data are usually clearly marked in the relevant part of the report. These data may be expressed in centimeters (cm) or millimeters (mm). Sometimes, a cross-sectional image of the cervix is attached to the B-ultrasound so that the doctor can more visually determine the shape and length of the cervix. 2. Determine the normal range of cervical length The normal range of cervical length varies with gestational age. Generally, in the second trimester (If pregnant 20 - 24 weeks), the cervical length should be greater than 30 mm (or 3 cm), which is considered a relatively safe range. However, cervical length decreases gradually with increasing gestational age. If cervical length is too short (If it is less than 25 mm), it may increase the risk of premature birth. 3. Comprehensive evaluation combined with other information When interpreting the cervical length information on the B-ultrasound, it is also necessary to combine the gestational age, pregnancy history, symptoms and other relevant examination results of the pregnant woman for comprehensive evaluation. For example, if a pregnant woman has a history of premature labor or is experiencing symptoms such as uterine contractions and vaginal bleeding, even if the cervical length is within the normal range, the doctor may take appropriate precautions according to the specific situation.