The timing of cervical cerclage is recommended by the American College of Obstetricians and Gynecologists (ACOG) in 2004 for elective cervical cerclage at 13 to 16 weeks of gestation in patients with a history of three or more unexplained midtrimester miscarriages and preterm deliveries. It is now generally accepted that the best time to perform cervical cerclage during pregnancy is between 13 and 17 weeks. If the procedure is performed before 12 weeks, it is likely to lead to miscarriage; if it is performed too late, the cervix is already dilated and the result is poor. It has been suggested that for women diagnosed with cervical insufficiency and those with high-risk factors for cervical insufficiency, cervical cerclage during pregnancy should be performed before 18 weeks of gestation, and that performing cervical cerclage before 18 weeks significantly improves the success rate of pregnancy.