Vol 94, No 1 (2023)
Research paper
Published online: 2022-12-02

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How does the type of delivery affect pelvic floor structure? MRI parameter-based anatomical study

Ayse Rabia Senkaya1, Eren Ismailoglu2, Sabahattin Anil Ari3, Ibrahim Karaca3
Pubmed: 36477780
Ginekol Pol 2023;94(1):57-63.


Objectives: The aim of this study is to examine the effects of delivery type and birth weight on pelvic floor structure using muscle defects, uterus-vagina angles and landmarks in pelvic magnetic resonance imaging (MRI). Material and methods: This is a retrospective study. Pelvic MR images of 38 vaginal deliveries and 62 cesarean section patients who met the study criteria were analyzed. Pubococcygeal line, H line, M line were marked on MR images, uterus cervix, cervix upper vagina, upper and middle vagina, middle and lower vagina angles, urogenital hiatus width, levator hiatus width, obturator internus muscle area, levator ani defect was measured. The urinary incontinence and pelvic organ prolapse examination findings were recorded. The patients' age, body mass index (BMI), parity, delivery type, maximum birth weight questions were asked. The data of both groups were compared. Results: Uterocervical angle and levator ani muscle defect was significantly higher in the vaginal delivery group (p < 0.001). In the vaginal delivery group, a significant positive correlation was found between the parity and the levator ani muscle defect (r = 0.552), (p = 0.000). A significant negative correlation was found between the parity and the uterocervical angle (r = −0.337), (p = 0.039). A significant negative correlation was found between maximum birth weight and cervix upper vagina angle (r = −0.365) (p = 0.024). In the vaginal delivery group, a negative significant correlation was found between birth weight and obturator internus muscle area (r = −0.378), (p = 0.019). Conclusions: These results show that cesarean section exposes the pelvic floor to less trauma and suggest that cesarean section may protect the pelvic floor.

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  1. Abrams P, Andersson KE, Birder L, et al. Fourth International Consultation on Incontinence Recommendations of the International Scientific Committee: Evaluation and treatment of urinary incontinence, pelvic organ prolapse, and fecal incontinence. Neurourol Urodyn. 2010; 29(1): 213–240.
  2. Cyr MP, Kruger J, Wong V, et al. Pelvic floor morphometry and function in women with and without puborectalis avulsion in the early postpartum period. Am J Obstet Gynecol. 2017; 216(3): 274.e1–274.e8.
  3. Chaliha C. Postpartum pelvic floor trauma. Curr Opin Obstet Gynecol. 2009; 21(6): 474–479.
  4. Kearney R, Sawhney R, DeLancey JOL. Levator ani muscle anatomy evaluated by origin-insertion pairs. Obstet Gynecol. 2004; 104(1): 168–173.
  5. Schwertner-Tiepelmann N, Thakar R, Sultan AH, et al. Obstetric levator ani muscle injuries: current status. Ultrasound Obstet Gynecol. 2012; 39(4): 372–383.
  6. Dietz HP. Quantification of major morphological abnormalities of the levator ani. Ultrasound Obstet Gynecol. 2007; 29(3): 329–334.
  7. Barnhart KT, Izquierdo A, Pretorius ES, et al. Baseline dimensions of the human vagina. Hum Reprod. 2006; 21(6): 1618–1622.
  8. Luo J, Betschart C, Ashton-Miller JA, et al. Quantitative analyses of variability in normal vaginal shape and dimension on MR images. Int Urogynecol J. 2016; 27(7): 1087–1095.
  9. Sammarco AG, Sheyn DD, Krantz TE, et al. A novel measurement of pelvic floor cross-sectional area in older and younger women with and without prolapse. Am J Obstet Gynecol. 2019; 221(5): 521.e1–521.e7.
  10. Sammarco AG, Sheyn D, Hong CX, et al. Pelvic cross-sectional area at the level of the levator ani and prolapse. Int Urogynecol J. 2021; 32(4): 1007–1013.
  11. Dolan LM, Hilton P. Obstetric risk factors and pelvic floor dysfunction 20 years after first delivery. Int Urogynecol J. 2010; 21(5): 535–544.
  12. Torrisi G, Minini G, Bernasconi F, et al. A prospective study of pelvic floor dysfunctions related to delivery. Eur J Obstet Gynecol Reprod Biol. 2012; 160(1): 110–115.
  13. Mant J, Painter R, Vessey M. Epidemiology of genital prolapse: observations from the Oxford Family Planning Association Study. Br J Obstet Gynaecol. 1997; 104(5): 579–585.
  14. Blomquist JL, Carroll M, Muñoz A, et al. Pelvic floor disorders 5-10 years after vaginal or cesarean childbirth. Obstet Gynecol. 2011; 118(4): 777–784.
  15. DeLancey JOL, Kearney R, Chou Q, et al. The appearance of levator ani muscle abnormalities in magnetic resonance images after vaginal delivery. Obstet Gynecol. 2003; 101(1): 46–53.
  16. Richter HE, Nygaard I, Burgio KL, et al. Pelvic Floor Disorders Network. Lower urinary tract symptoms, quality of life and pelvic organ prolapse: irritative bladder and obstructive voiding symptoms in women planning to undergo abdominal sacrocolpopexy for advanced pelvic organ prolapse. J Urol. 2007; 178(3 Pt 1): 965–9; discussion 969.
  17. Fritel X, Ringa V, Quiboeuf E, et al. Female urinary incontinence, from pregnancy to menopause: a review of epidemiological and pathophysiological findings. Acta Obstet Gynecol Scand. 2012; 91(8): 901–910.
  18. Afshari P, Dabagh F, Iravani M, et al. Comparison of pelvic floor muscle strength in nulliparous women and those with normal vaginal delivery and cesarean section. Int Urogynecol J. 2017; 28(8): 1171–1175.
  19. El Sayed RF. Magnetic resonance imaging of the female pelvic floor: anatomy overview, indications, and imaging protocols. Radiol Clin North Am. 2020; 58(2): 291–303.
  20. Volløyhaug I, Taithongchai A, Van Gruting I, et al. Levator ani muscle morphology and function in women with obstetric anal sphincter injury. Ultrasound Obstet Gynecol. 2019; 53(3): 410–416.
  21. Li S, Wen X, Gao Z, et al. Comparison of the axes and positions of the uterus and vagina between women with and without pelvic floor organ prolapse. Front Surg. 2022; 9: 760723.
  22. Krcmar M, Horcicka L, Nemec M, et al. Multilevel musculo-fascial defect magnetic resonance study of female pelvic floor: retrospective case control study in women with pelvic floor dysfunction after the first vaginal delivery. Acta Obstet Gynecol Scand. 2022; 101(6): 628–638.
  23. Rusavy Z, Paymova L, Kozerovsky M, et al. Levator ani avulsion: a Systematic evidence review (LASER). BJOG. 2022; 129(4): 517–528.
  24. Siahkal SF, Iravani M, Mohaghegh Z, et al. Investigating the association of the dimensions of genital hiatus and levator hiatus with pelvic organ prolapse: a systematic review. Int Urogynecol J. 2021; 32(8): 2095–2109.
  25. Reilly ETC, Freeman RM, Waterfield MR, et al. Prevention of postpartum stress incontinence in primigravidae with increased bladder neck mobility: a randomised controlled trial of antenatal pelvic floor exercises. BJOG. 2002; 109(1): 68–76.
  26. Harvey MA. Pelvic floor exercises during and after pregnancy: a systematic review of their role in preventing pelvic floor dysfunction. J Obstet Gynaecol Can. 2003; 25(6): 487–498.
  27. Boyadzhyan L, Raman SS, Raz S. Role of static and dynamic MR imaging in surgical pelvic floor dysfunction. Radiographics. 2008; 28(4): 949–967.