Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 Jul;32(7):1997-2003.
doi: 10.1007/s00192-021-04769-z. Epub 2021 Apr 2.

Finite element modeling of maximum stress in pelvic floor structures during the head expulsion (FINESSE) study

Affiliations

Finite element modeling of maximum stress in pelvic floor structures during the head expulsion (FINESSE) study

Hana Cechova et al. Int Urogynecol J. 2021 Jul.

Abstract

Introduction and hypothesis: Several studies have assessed birth-related deformations of the levator ani muscle (LAM) and perineum on models that depicted these elements in isolation. The main aim of this study was to develop a complex female pelvic floor computational model using the finite element method to evaluate points and timing of maximum stress at the LAM and perineum in relation to the birth process.

Methods: A three-dimensional computational model of the female pelvic floor was created and used to simulate vaginal birth based on data from previously described real-life MRI scans. We developed three models: model A (LAM without perineum); model B (perineum without LAM); model C (a combined model with both structures).

Results: The maximum stress in the LAM was achieved when the vertex was 9 cm below the ischial spines and measured 37.3 MPa in model A and 88.7 MPa in model C. The maximum stress in the perineum occurred at the time of distension by the suboocipito-frontal diameter and reached 86.7 MPa and 119.6 MPa in models B and C, respectively, while the stress in the posterior fourchette caused by the suboccipito-bregmatic diameter measured 36.9 MPa for model B and 39.8 MPa for model C.

Conclusions: Including perineal structures in a computational birth model simulation affects the level of stress at the LAM. The maximum stress at the LAM and perineum seems to occur when the head is lower than previously anticipated.

Keywords: Birth; Delivery; Levator; Modeling; Muscle; Partum; Perineal; Stress; Tension.

PubMed Disclaimer

References

    1. Blomquist JL, Muñoz A, Carroll M, Handa VL. Association of delivery mode with pelvic floor disorders after childbirth. JAMA-J Am Med Assoc. 2018;320:2438–47. https://doi.org/10.1001/jama.2018.18315 . - DOI
    1. Necesalova P, Karbanova J, Rusavy Z, et al. Mediolateral versus lateral episiotomy and their effect on postpartum coital activity and dyspareunia rate 3 and 6 months postpartum. Sex Reprod Healthc. 2016;8:25–30. https://doi.org/10.1016/j.srhc.2016.01.004 . - DOI - PubMed
    1. Larson KA, Yousuf A, Lewicky-Gaupp C, et al. Perineal body anatomy in living women: 3-dimensional analysis using thin-slice magnetic resonance imaging. Am J Obstet Gynecol. 2010;203:494.e15–21. https://doi.org/10.1016/j.ajog.2010.06.008 . - DOI
    1. Handa VL, Roem J, Blomquist JL, et al. Pelvic organ prolapse as a function of levator ani avulsion, hiatus size, and strength. Am J Obstet Gynecol. 2019;221:41.e1–7. https://doi.org/10.1016/j.ajog.2019.03.004 . - DOI
    1. Rizk DEE, Thomas L. Relationship between the length of the perineum and position of the anus and vaginal delivery in Primigravidae. Int Urogynecol J Pelvic Floor Dysfunct. 2000;11:79–83. https://doi.org/10.1007/s001920050074 . - DOI - PubMed

LinkOut - more resources