1 Wang SW,Ma LL,Huang S,et al.Role of cervical cerclage and vaginal progesterone in the treatment of cervical incompetence with/without preterm birth History.Chin Med J (Engl),2016,129:2670-2675. 2 Wu Y,Liang X,Cai M,et al.Development and validation of a model for individualized prediction of cervical insufficiency risks in patients undergoing IVF/ICSI treatment.Reprod Biol Endocrinol,2021,19:6. 3 Roman A,Suhag A,Berghella V.Overview of cervical insufficiency:diagnosis,etiologies,and risk factors.Clin Obstet Gynecol,2016,59:237-240. 4 Suhag A,Berghella V.Cervical cerclage.Clin Obstet Gynecol,2014,57:557-567. 5 Alfirevic Z,Stampalija T,Medley N.Cervical stitch (cerclage) for preventing preterm birth in singleton pregnancy.Cochrane Database Syst Rev,2017,6:CD008991. 6 Wang YY,Duan H,Zhang XN,et al.A novel cerclage insertion:modified laparoscopic transabdominal cervical cerclage with transvaginal removing (MLTCC-TR).J Minim Invasive Gynecol,2020,27:1300-1307. 7 Mi J,Liu F.Rate of caesarean section is alarming in China.Lancet,2014,383:1463-1464. 8 Li HT,Luo S,Trasande L,et al.Geographic variations and temporal trends in cesarean delivery rates in China,2008-2014. JAMA,2017,317:69-76. 9 Ye J,Zhang J,Mikolajczyk R,et al.Association between rates of caesarean section and maternal and neonatal mortality in the 21st century:a worldwide population-based ecological study with longitudinal data.BJOG,2016,123:745-753. 10 侯磊,李光辉,邹丽颖,等.全国剖宫产率及剖宫产指征构成比调查的多中心研究.中华妇产科杂志,2014,49:728-735. 11 Shin JE,Shin JC,Kim SJ,et al.Effect of cerclage on labor course and obstetric outcome:a case-control study.J Matern Fetal Neonatal Med,2012,25:1779-1782. 12 Parikh R,Brotzman S,Anasti JN.Cervical lacerations:some surprising facts.Am J Obstet Gynecol,2007,196:e17-18. 13 Landy HJ,Laughon SK,Bailit JL,et al.Characteristics associated with severe perineal and cervical lacerations during vaginal delivery.Obstet Gynecol,2011,117:627-635. 14 Operative Vaginal Birth:ACOG Practice Bulletin,Number 219. Obstet Gynecol,2020,135:e149-e159. 15 da Costa AO,Clode N,Graça LM.Elective removal of cervical cerclage and onset of spontaneous labor.Int J Gynaecol Obstet,2014,126:64-66. 16 Bisulli M,Suhag A,Arvon R,et al.Interval to spontaneous delivery after elective removal of cerclage.Am J Obstet Gynecol,2009,201:163.e1-4. 17 Ndubuisi VA,Ezugwu EC,Iyoke C.A ten year review of time interval between elective cervical cerclage removal at term and spontaneous onset of labour in Enugu,South-East Nigeria.J Obstet Gynaecol,2021,41:552-556. 18 Deanna J,Abuzied O,Islam F,et al.The place for prophylactic cerclage in the infertile patient with established cervical incompetence who conceived twins after septum reduction.Facts Views Vis Obgyn,2017,9:71-77. 19 Wu Y,Cai M,Liang X,et al.The prevalence of cervical insufficiency in Chinese women with polycystic ovary syndrome undergone ART treatment accompanied with negative prognosis:a retrospective study.J Obstet Gynaecol,2021,41:888-892. 20 李静.探讨早产危险因素、早产儿常见并发症及其预后,2019. 苏州大学.