Evidence map›Paper›PMID 35101408›Full record

ArticleAmerican journal of obstetrics and gynecology2022

On the management of maternal pushing during the second stage of labor: a biomechanical study considering passive tissue fatigue damage accumulation.

Maria C P Vila Pouca, João P S Ferreira, Marco P L Parente, Renato M Natal Jorge, James A Ashton-Miller

Open access · greenAbstract read
In one paragraph

Article in American journal of obstetrics and gynecology, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.

0numbers the graph read from it
0cells of the map it votes in
3citing papers in PubMed
2.6field-weighted citation impact, top 11% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

3 citing papers in PubMed, 13 citations in OpenAlex.

  1. Article
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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

5 authors at 2 institutions in 2 countries.

Maria C P Vila PoucaFaculty of Engineering, University of Porto, Porto, Portugal; Laboratório Associado de Energia, Transportes e Aeronáutica, Institute of Science and Innovation in Mechanical and Industrial Engineering, Porto, Portugal. Electronic address: maria.vp@fe.up.pt.
João P S FerreiraFaculty of Engineering, University of Porto, Porto, Portugal; Laboratório Associado de Energia, Transportes e Aeronáutica, Institute of Science and Innovation in Mechanical and Industrial Engineering, Porto, Portugal.
Marco P L ParenteFaculty of Engineering, University of Porto, Porto, Portugal; Laboratório Associado de Energia, Transportes e Aeronáutica, Institute of Science and Innovation in Mechanical and Industrial Engineering, Porto, Portugal.
Renato M Natal JorgeFaculty of Engineering, University of Porto, Porto, Portugal; Laboratório Associado de Energia, Transportes e Aeronáutica, Institute of Science and Innovation in Mechanical and Industrial Engineering, Porto, Portugal.
James A Ashton-MillerDepartments of Mechanical Engineering, University of Michigan, Ann Arbor, MI; Biomedical Engineering, University of Michigan, Ann Arbor, MI.
Universidade do Porto · PTUniversity of Michigan · US

Funding

Structure, Composition, & Histology Core - Core BP30AR069620 · NIAMS · UNIVERSITY OF MICHIGAN AT ANN ARBOR · PI KARL J JEPSEN · 2016 to 2026
$8.4M
A Phase 2 clinical study of the Materna device to shorten delivery time during childbirthR44HD096987 · NICHD · MATERNA MEDICAL · PI ASHFIELD, KELLY · 2018 to 2020
$2.2M
NIAMS NIH HHS P30 AR069620NICHD NIH HHS R44 HD096987
6 · The paper itself

Abstract

backgroundDuring the second stage of labor, the maternal pelvic floor muscles undergo repetitive stretch loading as uterine contractions and strenuous maternal pushes combined to expel the fetus, and it is not uncommon that these muscles sustain a partial or complete rupture. It has recently been demonstrated that soft tissues, including the anterior cruciate ligament and connective tissue in sheep pelvic floor muscle, can accumulate damage under repetitive physiological (submaximal) loads. It is well known to material scientists that this damage accumulation can not only decrease tissue resistance to stretch but also result in a partial or complete structural failure. Thus, we wondered whether certain maternal pushing patterns (in terms of frequency and duration of each push) could increase the risk of excessive damage accumulation in the pelvic floor tissue, thereby inadvertently contributing to the development of pelvic floor muscle injury.

objectiveThis study aimed to determine which labor management practices (spontaneous vs directed pushing) are less prone to accumulate damage in the pelvic floor muscles during the second stage of labor and find the optimum approach in terms of minimizing the risk of pelvic floor muscle injury. STUDY

designWe developed a biomechanical model for the expulsive phase of the second stage of labor that includes the ability to measure the damage accumulation because of repetitive physiological submaximal loads. We performed 4 simulations of the second stage of labor, reflecting a directed pushing technique and 3 alternatives for spontaneous pushing.

resultsThe finite element model predicted that the origin of the pubovisceral muscle accumulates the most damage and so it is the most likely place for a tear to develop. This result was independent of the pushing pattern. Performing 3 maternal pushes per contraction, with each push lasting 5 seconds, caused less damage and seemed the best approach. The directed pushing technique (3 pushes per contraction, with each push lasting 10 seconds) did not reduce the duration of the second stage of labor and caused higher damage accumulation.

conclusionThe frequency and duration of the maternal pushes influenced the damage accumulation in the passive tissues of the pelvic floor muscles, indicating that it can influence the prevalence of pelvic floor muscle injuries. Our results suggested that the maternal pushes should not last longer than 5 seconds and that the duration of active pushing is a better measurement than the total duration of the second stage of labor. Hopefully, this research will help to shed new light on the best practices needed to improve the experience of labor for women.

Indexed as

Delivery, ObstetricLabor Stage, SecondAnimalsFatigueFemaleHumansPelvic FloorPregnancySheepUterine Contractionfinite element methodlow-cycle fatigue failuremanagement of labormaternal pushespelvic floor musclesecond stage of laborvaginal delivery

Identifiers

PMID35101408
PMCPMC9308631
OpenAlexW4210560754

What OpenQuestion holds

Textmetadata
LicenceTDM
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.