Clinical and anamnestic risk factors for the formation of an incompetent scar after one cesarean section

Objective: determine the clinical and anamnestic risk factors leading to the formation of an incompetent uterine scar in patients after one previous cesarean section. Materials and methods: 102 histories of patients with a uterine scar after one cesarean section, 102 newborn charts, results of pathomorphological studies of the placentas for 2019–2020. All patients were divided into 3 groups: Group 1 (control) — 35 women with a uterine scar who gave birth vaginally; Group 2 (main group A) — 35 patients with established scar incompetence after one CS before delivery; Group 3 (main group B) — 32 patients with an unsuccessful attempt at vaginal delivery and intraoperatively established uterine scar incompetence after one CS. Results: It was established that an untenable scar on the uterus is associated with intrauterine interventions on the pelvic organs (p_1.2=0.031, OR_1.2=2.864; 95%CI=1.086–7.552), which were statistically significantly more common in group 2 compared with group 1. Inflammatory diseases of the pelvic organs in the anamnesis were statistically significantly more common in group 2 compared with group 1 (p_1.2=0.012, OR_1.2=3.778; 95%CI=1.308–10.913). In group 3 with an unsuccessful attempt at vaginal delivery, genital endometriosis was statistically significantly more common compared with study groups 1 and 2 (p_1.3=0.000001; p_2.3=0.00003) (OR_1.3=10.333. 95%CI=2.996–35.635; OR_2.3=22,000; 95%DEE=4,547–106–437). In group 3, inflammatory changes in the placenta were more often noted. The emergency nature of CS and the intergenetic interval of less than 2 years and 9 months were mainly in patients with uterine scar failure. One of the most frequent indications in emergency COP was a disproportion between the size of the mother's pelvis and the fetal head, which was noted in group 1 statistically significantly more often than in groups 2 and 3 of the study (p_1.2=0.0004; p_1.3=0.0003) (OR_1.2=10.074; 95%CI=2.595-39,112), (OR_1.3=8,982; 95%CI = 2,311-34,911). Complications in the postoperative period were statistically significantly more common in groups with uterine scar failure. Conclusion: the main clinical and anamnestic risk factors leading to the formation of an incompetent scar were: intrauterine interventions, genital endometriosis, emergency nature of the operation, pelvic-cephalic disproportion, short intergenetic interval.

1. Chen YT, Hsieh YC, Shen H, Cheng CH, Lee KH, Torng PL. Vaginal birth after cesarean section: Experience from a regional hospital. Taiwan J Obstet Gynecol. 2022;61(3):422-426. https://doi.org/10.1016/j.tjog.2022.03.006

2. Guo N, Bai RM, Qu PF, Huang P, He YP, et al. [Influencing factors and antenatal assessment of the vaginal birth after cesarean section]. Zhonghua Fu Chan Ke Za Zhi. 2019;54(6):369- 374. (In Chinese) https://doi.org/10.3760/cma.j.issn.0529-567x.2019.06.003

3. Krasnopol'skiĭ V.I., Buianova S.N., Shchukina N.A., Logutova L.S. Uterine suture (scar) incompetence after cesarean section: Problems and solutions (an editorial). Russian Bulletin of Obstetrician-Gynecologist. 2015;15(3):4 8. (In Russ.) https://doi.org/10.17116/rosakush20151534-8

4. Trojano G, Damiani GR, Olivieri C, Villa M, Malvasi A, et al. VBAC: antenatal predictors of success. Acta Biomed. 2019;90(3):300-309. https://doi.org/10.23750/abm.v90i3.7623

5. Thornton PD. VBAC calculator 2.0: Recent evidence. Birth. 2023;50(1):120-126. https://doi.org/10.1111/birt.12705

6. Gupta N, De A, Batra S. VBAC: Changes over Last 10 Years. J Obstet Gynaecol India. 2019;69(2):110-114. https://doi.org/10.1007/s13224-018-1101-0

7. Radzinskij V.E., Knyazev S.A. Sokratit' dolyu kesarevykh sechenii. Nastoyatel'nye rekomendatsii VOZ o snizhenii doli kesarevykh sechenii. StatusPraesens. Ginekologiya, akusherstvo, besplodnyi brak. 2015;(3):8–12. (in Russ.) eLIBRARY ID: 29254491 EDN: YQEOTH

8. Tanos V, Toney ZA. Uterine scar rupture – Prediction, prevention, diagnosis, and management. Best Pract Res Clin Obstet Gynaecol. 2019;59:115-131. https://doi.org/10.1016/j.bpobgyn.2019.01.009

9. ACOG Practice Bulletin No. 205: Vaginal Birth After Cesarean Delivery. Obstet Gynecol. 2019;133(2):e110-e127. https://doi.org/10.1097/AOG.0000000000003078

10. Savukyne E, Bykovaite-Stankeviciene R, Machtejeviene E, Nadisauskiene R, Maciuleviciene R. Symptomatic Uterine Rupture: A Fifteen Year Review. Medicina (Kaunas). 2020;56(11):574. https://doi.org/10.3390/medicina56110574

11. Guseva, О. I. Uterine ruptures: case analysis. Medical Almanac. 2018;(6):52-55. (In Russ.) eLIBRARY ID: 36574736 EDN: YQHPCX

12. Togioka BM, Tonismae T. Uterine Rupture. Treasure Island (FL): StatPearls Publishing; 2025. PMID: 32644635

13. Atia O, Rotem R, Reichman O, Jaffe A, Grisaru-Granovsky S, et al. Number of prior vaginal deliveries and trial of labor after cesarean success. Eur J Obstet Gynecol Reprod Biol. 2021;256:189-193. https://doi.org/10.1016/j.ejogrb.2020.11.009

14. Mi Y, Qu P, Guo N, Bai R, Gao J, et al. Evaluation of factors that predict the success rate of trial of labor after the cesarean section. BMC Pregnancy Childbirth. 2021;21(1):527. https://doi.org/10.1186/s12884-021-04004-z

15. Maroyi R, Naomi B, Moureau MK, Marceline BS, Ingersoll C, et al. Factors Associated with Successful Vaginal Birth After a Primary Cesarean Section in Women with an Optimal Inter-Delivery Interval. Int J Womens Health. 2021;13:903-909. https://doi.org/10.2147/IJWH.S334269

16. Wu Y, Kataria Y, Wang Z, Ming WK, Ellervik C. Factors associated with successful vaginal birth after a cesarean section: a systematic review and meta-analysis. BMC Pregnancy Childbirth. 2019;19(1):360. https://doi.org/10.1186/s12884-019-2517-y

17. Li YX, Bai Z, Long DJ, Wang HB, Wu YF, et al. Predicting the success of vaginal birth after caesarean delivery: a retrospective cohort study in China. BMJ Open. 2019;9(5):e027807. https://doi.org/10.1136/bmjopen-2018-027807

18. Fitzpatrick KE, Quigley MA, Kurinczuk JJ. Planned mode of birth after previous cesarean section: A structured review of the evidence on the associated outcomes for women and their children in high-income setting. Front Med (Lausanne). 2022;9:920647. https://doi.org/10.3389/fmed.2022.920647

19. Carauleanu A, Tanasa IA, Nemescu D, Socolov D. Risk management of vaginal birth after cesarean section (Review). Exp Ther Med. 2021;22(4):1111. https://doi.org/10.3892/etm.2021.10545

20. Downs S, Mokhtari N, Gold S, Ghofranian A, Kawakita T. Maternal and neonatal outcomes of trial of labor compared with elective cesarean delivery according to predicted likelihood of vaginal delivery. J Matern Fetal Neonatal Med. 2022;35(26):10487-10493. https://doi.org/10.1080/14767058.2022.2130239

21. Belogolovkin V, Crisan L, Lynch O, Weldeselasse H, August EM, et al. Neonatal outcomes of successful VBAC among obese and super-obese mothers. J Matern Fetal Neonatal Med. 2012;25(6):714-718. https://doi.org/10.3109/14767058.2011.596594

22. Shchukina N.A., Buianova S.N., Chechneva M.A., Zemskova N. Iu, Puchkova N.V., et al. Causes of a postcesarean incompetent uterine scar: a role of connective tissue dysplasia. Russian Bulletin of Obstetrician-Gynecologist. 2018;18(5):4 11. (In Russ.) https://doi.org/10.17116/rosakush2018180514

23. Okulova EO, Mikhelson AA, Melkozerova OA, Telyakova MI, Chistyakova GN, Lazukina MV. Endometriosis of a postcesarean incompetent of uterine scar: inflammatory or connective tissue dysplasia. Russian Journal of Human Reproduction. 2022;28(4):145-150. (In Russ.) https://doi.org/10.17116/repro202228041145

24. Tskhai V.B., Levanovich E.V., Kelberg V.G. Endometriosis of an untenable scar on the uterus after cesarean section. Obstetrics and gynecology. 2016;(8):119-123. (In Russ.) https://doi.org/10.18565/aig.2016.8.119-123

25. Savina L.V., Yashchuk A.G., Maslennikov A.V., Savin A.M., Shayakhmetov A.M. Risk factors for the formation of incompetent Scar on the uterus after Caesarean section. Meždunarodnyj naučno-issledovatel'skij žurnal (International Research Journal). 2022;6(120). https://doi.org/10.23670/IRJ.2022.120.6.050

26. Donnez O. Cesarean scar defects: management of an iatrogenic pathology whose prevalence has dramatically increased. Fertil Steril. 2020;113(4):704-716. https://doi.org/10.1016/j.fertnstert.2020.01.037

27. Geetha P. Induction of labour with prostaglandin E2 vaginal gel in women with one previous Сaesarean section. Middle East Fertility Society Journal. 2012;17:170–175. https://doi.org/10.1016/j.mefs.2012.04.001