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Alterations in pelvic floor muscles and pelvic organ support by pregnancy and vaginal delivery in squirrel monkeys

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Abstract

Introduction and hypothesis

The objective of this study was to measure the effects of pregnancy and parturition on pelvic floor muscles and pelvic organ support.

Methods

Levator ani, obturator internus, and coccygeus (COC) muscle volumes and contrast uptake were assessed by MRI of seven females prior to pregnancy, 3 days, and 4 months postpartum. Bladder neck and cervix position were measured dynamically with abdominal squeezing.

Results

The sides of three paired muscles were similar (p > 0.66). COC volumes were greater (p < 0.004) after parturition than before pregnancy or after recovery. COC contrast uptake increased (p < 0.02) immediately after delivery. Bladder neck position both in the relaxed state and abdominal pressure descended (p < 0.04) after delivery and descended further (p < 0.001) after recovery. Cervical position in the relaxed state before delivery was higher (p < 0.001) than postpartum but was unchanged (p = 0.50) with abdominal pressure relative to delivery.

Conclusion

In squirrel monkeys, coccygeus muscles demonstrate the greatest change related to parturition, and parturition-related bladder neck descent seems permanent.

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Acknowledgments

The authors acknowledge the assistance of Dr. Bobby L. Shull with concept review and manuscript commentary, Ms. Gina Du Par for editorial assistance, and Drs. Rebecca Blackwood and Jennifer Lane for veterinary assistance and animal anesthesia. Funding and animal resources for this study were provided by Enderly Endowment for Research in Urogynecology, Noble Centennial Endowment for Research in Obstetrics and Gynecology (TJK), and the NIH Squirrel Monkey Breeding and Research Resource.

Conflicts of interest

None.

Author information

Author notes

  1. Val M. Runge

    Present address: Department of Radiology, The University of Texas Medical Branch, 2.103 University Hospital Clinics, 301 University Boulevard, Galveston, TX, USA

Authors and Affiliations

  1. Departments of Obstetrics & Gynecology, Scott and White Memorial Hospital and Clinic, 2401 South 31st Street, Temple, TX, 76508, USA

    Jessica N. Bracken, Michelle Reyes, Lisa M. Pierce & Thomas J. Kuehl

  2. Department of Radiology, Scott and White Memorial Hospital and Clinic, Temple, TX, USA

    Jilene M. Gendron & Val M. Runge

  3. Department of Pathology, Scott and White Memorial Hospital and Clinic, Temple, TX, USA

    Thomas J. Kuehl

  4. Departments of Molecular & Cellular Medicine, Scott and White Memorial Hospital and Clinic, Temple, TX, USA

    Thomas J. Kuehl

  5. Texas A&M Health Science Center College of Medicine, Temple, TX, USA

    Jessica N. Bracken, Michelle Reyes, Jilene M. Gendron, Lisa M. Pierce, Val M. Runge & Thomas J. Kuehl

Authors
  1. Jessica N. Bracken
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  2. Michelle Reyes
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  3. Jilene M. Gendron
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  4. Lisa M. Pierce
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  5. Val M. Runge
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  6. Thomas J. Kuehl
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Corresponding author

Correspondence to Jessica N. Bracken.

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Bracken, J.N., Reyes, M., Gendron, J.M. et al. Alterations in pelvic floor muscles and pelvic organ support by pregnancy and vaginal delivery in squirrel monkeys. Int Urogynecol J 22, 1109–1116 (2011). https://doi.org/10.1007/s00192-011-1443-y

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  • DOI: https://doi.org/10.1007/s00192-011-1443-y

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