Birthweight and pelvic floor trauma after vaginal childbirth

  • Natalia Martinho
  • Talia Friedman
  • Friyan Turel
  • Kirsty Robledo
  • Cassio Riccetto
  • Hans Peter DietzEmail author
Original Article


Introduction and hypothesis

Birthweight seems to be a risk factor for levator ani muscle (LAM) avulsion and a predictive factor for pelvic organ prolapse (POP). Most trauma seems due to first vaginal birth.


One thousand one hundred twenty-five women with at least two vaginal deliveries underwent a physician-directed interview, followed by clinical examination (digital palpation and Pelvic Organ Prolapse Quantification-POPQ) and 4D translabial ultrasound. Ultrasound volume data were obtained at rest, on pelvic floor contraction and Valsalva. The investigator, blinded to all other data, performed offline analysis of the LAM integrity and hiatal area on Valsalva. We tested for associations between birthweight of the first and of the largest vaginally born baby on the one hand and avulsion and symptoms/signs of prolapse on the other hand.


Between July 2014 and July 2017, 1575 patients were seen. After exclusion of nulliparae and women with just one vaginal birth, 1202 remained. Another 77 were excluded due to missing data, leaving 1125. A significant association was found between birthweight and LAM avulsion as well as significant prolapse on POPQ. The birthweight of the first vaginally born baby was at least as predictive for avulsion as the birthweight of any subsequent births, even when adjusted for maternal age at first delivery and use of forceps.


The birthweight of the first vaginally born baby is associated with levator avulsion and subsequent POP. Maximum weight of vaginal births does not seem to be a stronger predictor.


Birthtrauma Birthweight Levator ani muscle avulsion Pelvic floor Pelvic organ prolapse Ultrasound 



The first author was the recipient of a scholarship sponsored by the Foundation of Research Support of the State of Sao Paulo, Brazil (FAPESP process 2015/22521–8 and 2017/02565–6) during her visit at the Pelvic Floor Unit, Nepean Hospital, University of Sydney, Australia.

Compliance with ethical standards

Conflicts of interest

HP Dietz has received paid travel expenses and honoraria from GE Medical.


  1. 1.
    Dietz HP, Franco AV, Shek KL, Kirby A. Avulsion injury and levator hiatal ballooning: two independent risk factors for prolapse? An observational study. Acta Obstet Gynecol Scand. 2012;91(2):211–4. Scholar
  2. 2.
    Van Delft K, Sultan AH, Thakar R, Schwertner-Tiepelmann N, Kluivers K. The relationship between postpartum levator ani muscle avulsion and signs and symptoms of pelvic floor disorders. BJOG. 2014;121(9):1164–71. CrossRefGoogle Scholar
  3. 3.
    Volløyhaug I, Mørkved S, Salvessen KA. Association between pelvic floor muscle trauma and pelvic organ prolapse 20 years after delivery. Int Urogynecol J. 2016;27(1):39–45. Scholar
  4. 4.
    Abdool Z, Dietz HP, Lindeque BG. Prolapse symptoms are associated with abnormal functional anatomy of the pelvic floor. Int Urogynecol J. 2017;28(9):1387–91. Scholar
  5. 5.
    Lien KC, Mooney B, DeLancey JO, Ashton-Miller JA. Levator ani muscle stretch induced by simulated vaginal birth. Obstet Gynecol. 2004;103(1):31–40. Scholar
  6. 6.
    Svabik K, Shek KL, Dietz HP. How much does the puborectalis muscle have to stretch during childbirth? BJOG. 2009;116(12):1657–62. Scholar
  7. 7.
    Shek KL, Dietz HP. The effect of childbirth on hiatal dimensions. Obstet Gynecol. 2009;113(6):1272–8. Scholar
  8. 8.
    Dietz HP. Pelvic floor trauma in childbirth. Aust N Z J Obstet Gynaecol. 2013;53(3):220–30. Scholar
  9. 9.
    Friedman T, Eslick G, Dietz HP. Risk factors for prolapse recurrence—systematic review and meta-analysis. Int Urogynecol J. 2018;29(1):13–21. Scholar
  10. 10.
    Horak TA, Guzman-Rojas R, Shek KL, Dietz HP. Pelvic floor trauma: does the second baby matter? Ultrasound Obstet Gynecol. 2014;44(1):90–4. Scholar
  11. 11.
    Kamisan Atan I, Lin S, Herbison P, Dietz HP. Wilson PD for the PROLONG study group: it is the first birth that does the damage: a cross-sectional study 20 years after delivery. Int Urogynecol J. 2018;29:1637–43. Scholar
  12. 12.
    Rahmanou P, Caudwell-Hall J, Kamisan Atan I, Dietz HP. The association between maternal age at first delivery and risk of obstetric trauma. Am J Obstet Gynecol. 2016;215(4):451.e1–7. Scholar
  13. 13.
    Dietz HP. Forceps: towards obsolescence or revival? Acta Obstet Gynecol Scand. 2015;94(4):347–51. Scholar
  14. 14.
    Garcia-Mejido JA, Gutierrez-Palomino L, Borrero C, Valdivieso P, Fernandez-Palacin A, Sainz-Bueno JA. Factors that influence the development of avulsion of the levator ani muscle in eutocic deliveries: 3-4D transperineal ultrasound study. J Matern Fetal Neonatal Med. 2016;29(19):3183–6. Google Scholar
  15. 15.
    Rodriguez-Mias NL, Martinez-Franco E, Aguado J, Sanchez E, Amat-Tardiu L. Pelvic organ prolapse and stress urinary incontinence: do they share the same risk factors? Eur J Obstet Gynecol Reprod Biol. 2015;190:52–7. Scholar
  16. 16.
    Laycock J, Jerwood D. Pelvic floor muscle assessment: the PERFECT scheme. Physiotherapy. 2001;87(12):631–42. Scholar
  17. 17.
    Bump RC, Mattiasson A, Bø K, et al. The standardization of terminology of female pelvic organ prolapse and pelvic floor dysfunction. Am J Obstet Gynecol. 1996;175(1):10–7.CrossRefGoogle Scholar
  18. 18.
    Dietz HP. Pelvic organ prolapse—a review. Aust Fam Physician. 2015;44(7):446–52.Google Scholar
  19. 19.
    Dietz HP. Pelvic floor ultrasound: a review. Clin Obstet Gynecol. 2017;60(1):58–81. Scholar
  20. 20.
    Dietz HP, Shek KL. Tomographic ultrasound imaging of the pelvic floor: which levels matter most? Ultrasound Obstet Gynecol. 2009;33(6):698–703. Scholar
  21. 21.
    Dietz HP, Bernardo MJ, Kirby A, Shek KL. Minimal criteria for the diagnosis of avulsion of the puborectalis muscle by tomographic ultrasound. Int Urogynecol J. 2011;22(6):699–704. Scholar
  22. 22.
    Dietz HP, Wong V, Shek KL. A simplified method for determining hiatal biometry. Aust N Z J Obstet Gynaecol. 2011;51(6):540–3. Scholar
  23. 23.
    DeLong ER, DeLong DM, Clarke-Pearson DL. Comparing the areas under two or more correlated receiver operating characteristic curves: a nonparametric approach. Biometrics. 1988;44(3):837–45.CrossRefGoogle Scholar
  24. 24.
    Girgis B, Kamisan Atan I, Shek KL, Dietz HP. How to determine “ballooning” of the levator hiatus on clinical examination: a retrospective observational study. Int Urogynecol J. 2013;24(11):1933–7. Scholar
  25. 25.
    Turel F, Caagbay D, Dietz HP. The prevalence of major birth trauma in Nepali women. J Ultrasound Med. 2018; Accepted 27.2.18.Google Scholar
  26. 26.
    Valsky DV, Lipschuetz M, Bord A, 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):91.e1–7. Scholar
  27. 27.
    Svabik K, Shek KL, Dietz HP. How much does the puborectalis muscle have to stretch during childbirth? BJOG. 2009;116:1657–62.CrossRefGoogle Scholar
  28. 28.
    Tegerstedt G, Miedel A, Mæhle-Schmidt M, Nyrén O, Hammarstrom M. Obstetric risk factors for symptomatic prolapse: a population-based approach. Am J Obstet Gynecol. 2006;194(1):75–81. Scholar
  29. 29.
    Swift SE, Pound T, Dias JK. Case-control study of etiologic factors in the development of severe pelvic organ prolapse. Int Urogynecol J Pelvic Floor Dysfunct. 2001;12(3):187–92.CrossRefGoogle Scholar
  30. 30.
    Kapaya H, Hashim S, Jha S. OASI: a preventable injury? Eur J Obstet Gynecol Reprod Biol. 2015;185:9–12. Scholar
  31. 31.
    Wilson D, Dornan J, Milsom I, Freeman R. UR-CHOICE: can we provide mothers-to-be with information about the risk of future pelvic floor dysfunction? Int Urogynecol J. 2014;25(11):1449–52. Scholar
  32. 32.
    Trutnowski G, Guzman Rojas R, Martin A, Dietz HP. Pelvic floor dysfunction—the role of menopause. Maturitas. 2013 Oct;76(2):134–8.CrossRefGoogle Scholar

Copyright information

© The International Urogynecological Association 2019

Authors and Affiliations

  • Natalia Martinho
    • 1
  • Talia Friedman
    • 2
  • Friyan Turel
    • 2
  • Kirsty Robledo
    • 3
  • Cassio Riccetto
    • 1
  • Hans Peter Dietz
    • 2
    • 4
    Email author
  1. 1.Faculty of Medical SciencesState University of Campinas – UNICAMPCampinasBrazil
  2. 2.Sydney Medical School NepeanUniversity of SydneySydneyAustralia
  3. 3.NHMRC Clinical Trials CentreUniversity of SydneySydneyAustralia
  4. 4.Sydney Medical School NepeanNepean HospitalPenrithAustralia

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