Check cervical canal length 28mm at 28 weeks of pregnancy it is best to have more bed rest and less activity. Predicting preterm labor is usually done at 24 weeks of pregnancy transvaginal ultrasound to measure the cervical length, greater than 30mm is normal, preterm labor is less likely. Less than 25mm is a high risk of preterm labor, if there is a history of late miscarriage, you can go to the hospital for cervical cerclage. Cervical canal length measured at 28 weeks of pregnancy is 28mm, less than 30mm, there is also a risk of preterm labor, but not to the extent of the need for cervical cerclage. If there are no symptoms of labor such as abdominal pain and vaginal bleeding, you can observe. However, you should pay more attention to bed rest and less activity, especially not strenuous exercise. Oral progesterone soft gelatin capsules can also be taken to stabilize the uterus, subject to medical advice. In addition, pregnant women must undergo regular checkups, so that any abnormalities can be detected in time and the obstetrician can be consulted.