Cervical cerclage: history-indicated, ultrasound-indicated and rescue

She is 21 weeks, her second pregnancy, and she lost the first at 22 weeks after "a bit of pressure and then it just happened". Today she says she feels heavy. You put in a speculum and see membranes at the external os. Everything you do in the next hour — the swabs, the questions, the decision, the words you use — is in this topic.^[1][9]

Overview and definition

A cerclage is a suture placed around the cervix to reduce second-trimester loss and preterm birth. It was first performed in 1902, and we are still arguing about who benefits.^[1]

Cervical insufficiency is an imprecise diagnosis, and saying so out loud earns marks. The old model — a cervix that is mechanically "weak" and simply gives way — is too crude. Current thinking treats cervical integrity as a continuum, influenced not only by intrinsic structure but by the inflammatory processes driving premature effacement and dilatation.^[1]

That reframing has a practical payoff. If the cervix is partly a barrier rather than only a strut, then a cerclage works in two ways: it gives some structural support, and it maintains cervical length and the endocervical mucus plug as a mechanical barrier to ascending infection. The second mechanism may matter more — and it predicts exactly how cerclage fails.^[1]

References17ShowHide

1. [1]Shennan AH, Story L Cervical Cerclage: Green-top Guideline No. 75 BJOG, 2022.PMID 35199905
2. [2]Alfirevic Z, Stampalija T, Medley N Cervical stitch (cerclage) for preventing preterm birth in singleton pregnancy Cochrane Database Syst Rev, 2017.PMID 28586127
3. [3]MRC/RCOG Working Party on Cervical Cerclage Final report of the Medical Research Council/Royal College of Obstetricians and Gynaecologists multicentre randomised trial of cervical cerclage. MRC/RCOG Working Party on Cervical Cerclage Br J Obstet Gynaecol, 1993.PMID 8334085
4. [4]Berghella V, Rafael TJ, Szychowski JM, et al. Cerclage for short cervix on ultrasonography in women with singleton gestations and previous preterm birth: a meta-analysis Obstet Gynecol, 2011.PMID 21446209
5. [5]Berghella V, Odibo AO, To MS, et al. Cerclage for short cervix on ultrasonography: meta-analysis of trials using individual patient-level data Obstet Gynecol, 2005.PMID 15994635
6. [6]Owen J, Hankins G, Iams JD, et al. Multicenter randomized trial of cerclage for preterm birth prevention in high-risk women with shortened midtrimester cervical length Am J Obstet Gynecol, 2009.PMID 19788970
7. [7]To MS, Alfirevic Z, Heath VC, et al. Cervical cerclage for prevention of preterm delivery in women with short cervix: randomised controlled trial Lancet, 2004.PMID 15183621
8. [8]Althuisius SM, Dekker GA, Hummel P, van Geijn HP Cervical incompetence prevention randomized cerclage trial: emergency cerclage with bed rest versus bed rest alone Am J Obstet Gynecol, 2003.PMID 14586323
9. [9]Ehsanipoor RM, Seligman NS, Saccone G, et al. Physical Examination-Indicated Cerclage: A Systematic Review and Meta-analysis Obstet Gynecol, 2015.PMID 26241265
10. [10]Hodgetts Morton V, Toozs-Hobson P, Moakes CA, et al. Monofilament suture versus braided suture thread to improve pregnancy outcomes after vaginal cervical cerclage (C-STICH): a pragmatic randomised, controlled, phase 3, superiority trial Lancet, 2022.PMID 36273481
11. [11]Shennan A, Chandiramani M, Bennett P, et al. MAVRIC: a multicenter randomized controlled trial of transabdominal vs transvaginal cervical cerclage Am J Obstet Gynecol, 2020.PMID 31585096
12. [12]Hezelgrave NL, Suff N, Seed P, et al. Comparing cervical cerclage, pessary and vaginal progesterone for prevention of preterm birth in women with a short cervix (SuPPoRT): A multicentre randomised controlled trial PLoS Med, 2024.PMID 39012912
13. [13]Zullo F, Di Mascio D, Chauhan SP, et al. Removal versus retention of cervical cerclage with preterm prelabor rupture of membranes: Systematic review and meta-analysis Eur J Obstet Gynecol Reprod Biol, 2023.PMID 37481990
14. [14]American College of Obstetricians and Gynecologists Prediction and Prevention of Spontaneous Preterm Birth: ACOG Practice Bulletin, Number 234 Obstet Gynecol, 2021.PMID 34293771
15. [15]Rafael TJ, Berghella V, Alfirevic Z Cervical stitch (cerclage) for preventing preterm birth in multiple pregnancy Cochrane Database Syst Rev, 2014.PMID 25208049
16. [16]Jorgensen AL, Alfirevic Z, Tudur Smith C, et al. Cervical stitch (cerclage) for preventing pregnancy loss: individual patient data meta-analysis BJOG, 2007.PMID 17903224
17. [17]D'Antonio F, Eltaweel N, Prasad S, et al. Cervical cerclage for prevention of preterm birth and adverse perinatal outcome in twin pregnancies with short cervical length or cervical dilatation: A systematic review and meta-analysis PLoS Med, 2023.PMID 37535682