E M Joyce1, P Diaz2, S Tamarkin3, R Moore4, A Strohl4, B Stetzer5, D Kumar4, M S Sacks6, J J Moore7. 1. Department of Bioengineering, Swanson School of Engineering, School of Medicine, University of Pittsburgh, Pittsburgh PA, USA. 2. Department of Radiology, MetroHealth Medical Center and Case Western Reserve University, USA; Department of Biomedical Engineering, Case Western Reserve University, USA. 3. Department of Radiology, MetroHealth Medical Center and Case Western Reserve University, USA. 4. Department of Pediatrics, MetroHealth Medical Center and Case Western Reserve University, USA. 5. Department of Reproductive Biology, MetroHealth Medical Center and Case Western Reserve University, Cleveland, OH, USA. 6. Department of Biomedical Engineering and the Institute for Computational Engineering and Sciences, The University of Texas at Austin, Austin, TX 78712-0027, USA. 7. Department of Pediatrics, MetroHealth Medical Center and Case Western Reserve University, USA; Department of Reproductive Biology, MetroHealth Medical Center and Case Western Reserve University, Cleveland, OH, USA. Electronic address: jmoore@metrohealth.org.
Abstract
INTRODUCTION: Fetal membranes (FM) usually fail prior to delivery during term labor, but occasionally fail at preterm gestation, precipitating preterm birth. To understand the FM biomechanical properties underlying these events, study of the baseline in-vivo stretch experienced by the FM is required. This study's objective was to utilize high resolution MRI imaging to determine in-vivo FM stretch. METHODS: Eight pregnant women (38.4 ± 0.4wks) underwent abdominal-pelvic MRI prior to (2.88 ± 0.83d) caesarean delivery. Software was utilized to determine the total FM in-vivo surface area (SA) and that of its components: placental disc and reflected FM. At delivery, the SA of the disc and FM in the relaxed state were measured. In-vivo (stretched) to delivered SA ratios were calculated. FM fragments were then biaxially stretched to determine the force required to re-stretch the FM back to in-vivo SA. RESULTS: Total FM SA, in-vivo vs delivered, was 2135.51 ± 108.47 cm(2) vs 842.59 ± 35.86 cm(2); reflected FM was 1778.42 ± 107.39 cm(2) vs 545.41 ± 22.90 cm(2), and disc was 357.10 ± 28.08 cm(2) vs 297.18 ± 22.14 cm(2). The ratio (in-vivo to in-vitro SA) of reflected FM was 3.26 ± 0.11 and disc was 1.22 ± 0.10. Reflected FM re-stretched to in-vivo SA generated a tension of 72.26 N/m, corresponding to approximate pressure of 15.4 mmHg. FM rupture occurred at 295.08 ± 31.73 N/m corresponding to approximate pressure of 34 mmHg. Physiological SA was 70% of that at rupture. DISCUSSION: FM are significantly distended in-vivo. FM collagen fibers were rapidly recruited once loaded and functioned near the failure state during in-vitro testing, suggesting that, in-vivo, minimal additional (beyond physiological) stretch may facilitate rapid, catastrophic failure.
INTRODUCTION: Fetal membranes (FM) usually fail prior to delivery during term labor, but occasionally fail at preterm gestation, precipitating preterm birth. To understand the FM biomechanical properties underlying these events, study of the baseline in-vivo stretch experienced by the FM is required. This study's objective was to utilize high resolution MRI imaging to determine in-vivo FM stretch. METHODS: Eight pregnant women (38.4 ± 0.4wks) underwent abdominal-pelvic MRI prior to (2.88 ± 0.83d) caesarean delivery. Software was utilized to determine the total FM in-vivo surface area (SA) and that of its components: placental disc and reflected FM. At delivery, the SA of the disc and FM in the relaxed state were measured. In-vivo (stretched) to delivered SA ratios were calculated. FM fragments were then biaxially stretched to determine the force required to re-stretch the FM back to in-vivo SA. RESULTS: Total FM SA, in-vivo vs delivered, was 2135.51 ± 108.47 cm(2) vs 842.59 ± 35.86 cm(2); reflected FM was 1778.42 ± 107.39 cm(2) vs 545.41 ± 22.90 cm(2), and disc was 357.10 ± 28.08 cm(2) vs 297.18 ± 22.14 cm(2). The ratio (in-vivo to in-vitro SA) of reflected FM was 3.26 ± 0.11 and disc was 1.22 ± 0.10. Reflected FM re-stretched to in-vivo SA generated a tension of 72.26 N/m, corresponding to approximate pressure of 15.4 mmHg. FM rupture occurred at 295.08 ± 31.73 N/m corresponding to approximate pressure of 34 mmHg. Physiological SA was 70% of that at rupture. DISCUSSION: FM are significantly distended in-vivo. FM collagen fibers were rapidly recruited once loaded and functioned near the failure state during in-vitro testing, suggesting that, in-vivo, minimal additional (beyond physiological) stretch may facilitate rapid, catastrophic failure.
Authors: M Lappas; T L Odumetse; C Riley; N G Reti; S J Holdsworth-Carson; G E Rice; M Permezel Journal: Placenta Date: 2008-10-25 Impact factor: 3.481
Authors: Hannah Blencowe; Simon Cousens; Mikkel Z Oestergaard; Doris Chou; Ann-Beth Moller; Rajesh Narwal; Alma Adler; Claudia Vera Garcia; Sarah Rohde; Lale Say; Joy E Lawn Journal: Lancet Date: 2012-06-09 Impact factor: 79.321
Authors: R M Moore; F Schatz; D Kumar; B M Mercer; A Abdelrahim; N Rangaswamy; C Bartel; J M Mansour; C J Lockwood; J J Moore Journal: Placenta Date: 2010-08-14 Impact factor: 3.481
Authors: D Kumar; F Schatz; R M Moore; B M Mercer; N Rangaswamy; J M Mansour; C J Lockwood; J J Moore Journal: Placenta Date: 2011-03 Impact factor: 3.481
Authors: Robert M Moore; Jillian B Novak; Deepak Kumar; Joseph M Mansour; Brian M Mercer; John J Moore Journal: Biol Reprod Date: 2008-12-23 Impact factor: 4.285
Authors: Li Liu; Hope L Johnson; Simon Cousens; Jamie Perin; Susana Scott; Joy E Lawn; Igor Rudan; Harry Campbell; Richard Cibulskis; Mengying Li; Colin Mathers; Robert E Black Journal: Lancet Date: 2012-05-11 Impact factor: 79.321
Authors: Erin Marie Louwagie; Lindsey Carlson; Veronica Over; Lu Mao; Shuyang Fang; Andrea Westervelt; Joy Vink; Timothy Hall; Helen Feltovich; Kristin Myers Journal: PLoS One Date: 2021-01-28 Impact factor: 3.240
Authors: Chasey Omere; Lauren Richardson; George R Saade; Elizabeth A Bonney; Talar Kechichian; Ramkumar Menon Journal: Front Physiol Date: 2020-07-24 Impact factor: 4.566