What is a short cervical canal? Generally, before 24 weeks of pregnancy, if the cervical length is less than 0.98 inches (25 millimeters), or there is a funnel formation at the internal os of the cervix accompanied by cervical canal shortening, it indicates an increased risk of preterm birth.

If a woman has a typical history of three or more second - trimester spontaneous abortions or preterm births, a prophylactic cervical cerclage is generally recommended between 12 and 14 weeks of pregnancy.

If a physical examination during the second trimester of pregnancy, after excluding labor and placental abruption, reveals that the cervix has dilated, an emergency cervical cerclage can be performed after excluding infection and other contraindications.

The ultrasound indication is usually a cervical length of less than 0.98 inches (25 millimeters) at 24 weeks, and a cervical cerclage can be performed based on this ultrasound finding.

After cervical cerclage, tocolytic treatment can be carried out. Vaginal administration of micronized progesterone vaginal suppositories, once a night from 16 weeks to 36 weeks of pregnancy, is an option.

After the cerclage, the suture should generally be removed when the pregnancy reaches 37 weeks or later.