Vaginal birth after cesarean section and levator ani avulsion

Czech version

Authors: L. Paymová ^1,2; V. Kališ ^1,2; T. Šperlová ²; V. Nová ³; Z. Rušavý ^1,2
Authors‘ workplace: Gynekologicko‑porodnická klinika FN a LF UK, Plzeň, přednosta doc. MUDr. Z. Novotný CSc. ¹; Lékařská fakulta Univerzity Karlovy, Plzeň ²; Gynekologické oddělení Nemocnice Hořovice, NH Hospital a. s., primář MUDr. L. Teslík, I. F. E. P. A. G. ³
Published in: Ceska Gynekol 2020; 85(5): 296-301
Category:

Overview

Objective: The aim of the study was to assess the risk of levator ani avulsion in vaginal birth after cesarean section (VBAC).

Design: Observational cohort study.

Settings: Department of Gynecology and Obstetrics, Medical Faculty, Charles University and University Hospital Pilsen.

Methodology: In this observational study we included every secundiparous woman after her first VBAC at term from 2012 till 2016 at our tertiary center. Women after repeated VBAC, delivering preterm or women after stillbirth were excluded. In addition, we enrolled random primiparous women as a control group. The women were invited for a 4D pelvic floor ultrasound for acquisition of a 4D volume of their pelvic floor at rest and during Valsalva. The levator avulsion was diagnosed off-line from the volumes of the pelvic floor during contraction, area of the urogenital hiatus was measured at rest and Valsalva. The laterality of the avulsion was additionally noted. The cohorts were then compared using Chi-square test and Wilcoxon two-sample test according to the distribution of normality, p-value < 0.05 was considered statistically significant.

Results: Total of 255 women after VBAC in the study period were enrolled in the study based on the inclusion and exclusion criteria. All of them were contacted, 98 (38.4%) came for the examination. The main reason for additional exclusion was another pregnancy or delivery and lack of interest in the study. In addition, 69 random women after first vaginal delivery were examined as a control group. No statistically significant differences in group characteristics apart from the age at the time of birth (32.7 vs. 30.0 years, p < 0.05) were found between VBAC and the Controls. The difference in levator avulsion and ballooning rate did not reach statistical significance. The variance of area of the urogenital hiatus in rest and during Valsalva was similar in both groups.

Conclusion: VBAC is not associated with an increased risk of levator ani avulsion compared to primaparous women.

Keywords:

pelvic floor – musculus levator ani – 4D transperineal ultrasound – avulsion injury – VBAC

Sources

1. Betran, AP., et al. WHO Statement on Caesarean Section Rates. BJOG, 2016, 123(5), p. 667–670.

2. Brandon, C., et al. Pubic bone injuries in primiparous women: magnetic resonance imaging in detection and differential diagnosis of structural injury. Ultrasound Obstet Gynecol, 2012, 39(4), p. 444–451.

3. Cassado Garriga, J., et al. Four-dimensional sonographic evaluation of avulsion of the levator ani according to delivery mode. Ultrasound Obstet Gynecol, 2011, 38(6), p. 701–706.

4. Declercq, E., Cabral, H., Ecker, J. The plateauing of cesarean rates in industrialized countries. Am J Obstet Gynecol, 2017, 216(3), p. 322–323.

5. DeLancey, JO., et al. The appearance of levator ani muscle abnormalities in magnetic resonance images after vaginal delivery. Obstet Gynecol, 2003, 101(1), p. 46–53.

6. Derpapas, A., et al. Prevalence of pubovisceral muscle avulsion in a general gynecology cohort: a computed tomography (CT) study. Neurourol Urodyn, 2013, 32(4), p. 359–362.

7. Dietz, HP. Pelvic floor trauma in childbirth. Aust N Z J Obstet Gynaecol, 2013, 53(3), p. 220–230.

8. Dietz, HP. Quantification of major morphological abnormalities of the levator ani. Ultrasound Obstet Gynecol, 2007, 29(3), p. 329–334.

9. Dietz, HP. Ultrasound in the assessment of pelvic organ prolapse. Best Pract Res Clin Obstet Gynaecol, 2019, 54, p. 12–30.

10. Dietz, HP., Shek, C., Clarke, B. Biometry of the pubovisceral muscle and levator hiatus by three-dimensional pelvic floor ultrasound. Ultrasound Obstet Gynecol, 2005, 25(6), p. 580–585.

11. Dietz, HP., Shek, KL. Tomographic ultrasound imaging of the pelvic floor: which levels matter most? Ultrasound Obstet Gynecol, 2009, 33(6), p. 698–703.

12. Durnea, CM., et al. Status of the pelvic floor in young primiparous women. Ultrasound Obstet Gynecol, 2015, 46(3), p. 356–362.

13. Guise, JM., et al. Vaginal birth after cesarean: new insights. Evid Rep Technol Assess (Full Rep), 2010, 191, p. 1–397.

14. Hehir, MP., et al. Are women having a vaginal birth after a previous caesarean delivery at increased risk of anal sphincter injury? BJOG, 2014, 121(12), p. 1515–1520.

15. Horak, TA., et al. Pelvic floor trauma: does the second baby matter? Ultrasound Obstet Gynecol, 2014, 44(1), p. 90–94.

16. Chan, SS., et al. Pelvic floor biometry during a first singleton pregnancy and the relationship with symptoms of pelvic floor disorders: a prospective observational study. BJOG, 2014, 121(1), p. 121–129.

17. Kearney, R., et al. Obstetric factors associated with levator ani muscle injury after vaginal birth. Obstet Gynecol, 2006, 107(1), p. 144–149.

18. Novellas, S., et al. MR features of the levator ani muscle in the immediate postpartum following cesarean delivery. Int Urogynecol J, 2010, 21(5), p. 563–568.

19. Raisanen, S., et al. A prior cesarean section and incidence of obstetric anal sphincter injury. Int Urogynecol J, 2013, 24(8), p. 1331–1339.

20. Rodrigo, N., et al. The use of 3-dimensional ultrasound of the pelvic floor to predict recurrence risk after pelvic reconstructive surgery. Aust N Z J Obstet Gynaecol, 2014, 54(3), p. 206–211.

21. Rusavy, Z., et al. Timing of cesarean and its impact on labor duration and genital tract trauma at the first subsequent vaginal birth: a retrospective cohort study. BMC Pregnancy Childbirth, 2019, 19(1), p. 207.

22. Shi, M., et al. MRI changes of pelvic floor and pubic bone observed in primiparous women after childbirth by normal vaginal delivery. Arch Gynecol Obstet, 2016, 294(2), p. 285–289.

23. Snooks, SJ., et al. Risk factors in childbirth causing damage to the pelvic floor innervation. Int J Colorectal Dis, 1986, 1(1), p. 20–24.

24. Thibault-Gagnon, S., et al. Do women notice the impact of childbirth-related levator trauma on pelvic floor and sexual function? Results of an observational ultrasound study. Int Urogynecol J, 2014, 25(10), p. 1389–1398.

25. Urbankova, I., et al. The effect of the first vaginal birth on pelvic floor anatomy and dysfunction. Int Urogynecol J, 2019, 30(10), p. 1689–1696.

26. Valsky, DV., et al. Fetal head circumference and length of second stage of labor are risk factors for levator ani muscle injury, diagnosed by 3-dimensional transperineal ultrasound in primiparous women. Am J Obstet Gynecol, 2009, 201(1), p. 91 e1–7.

27. van Delft, K., et al. Levator ani muscle avulsion during childbirth: a risk prediction model. BJOG, 2014, 121(9), p. 1155–1163; discussion 1163.

28. Zhang, J., et al. Contemporary cesarean delivery practice in the United States. Am J Obstet Gynecol, 2010, 203(4), p. 326.