Pudendal nerve stretch during vaginal birth: A 3D computer simulation

Lien, Kuo Cheng; Morgan, Daniel M.; DeLancey, John O.L.; Ashton‐Miller, James A.

doi:10.1016/j.ajog.2005.01.032

Cited by 141 publications

(67 citation statements)

References 17 publications

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“…Various investigators have identified connective tissue disruption, muscle fiber hypoxia, nerve compression injury, among others. [4,5] Direct damage to pelvic floor musculature has been suggested by computer models of parturition, which simulate the fetal head causing stretching of the levator ani complex to potentially injurious lengths. This stretching could result in a tearing of the muscle body, detachment from its bony insertions, and neuropathic injury.…”

Section: Introductionmentioning

confidence: 99%

Levator ani abnormality 6 weeks after delivery persists at 6 months

Branham

Thomas

Jaffe

et al. 2007

American Journal of Obstetrics and Gynecology

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Objective: Assess post partum changes in the levator ani muscle using magnetic resonance (MR) imaging and relate these changes to obstetrical events and risk factors associated with pelvic floor dysfunction.Study Design: A board certified radiologist specializing in abdominal imaging evaluated 146 pelvic MR studies from 57 primiparas 6 weeks and 6 months after first obstetrical delivery and 32 nulliparas. A yes/no determination of muscle body and insertion integrity, muscle thinning, and measurement of muscle thickness in mm was made for each of four muscle sites: right and left puborectalis, right and left ileococcygeous.Incidence of muscle abnormality and mean muscle thickness were tested in pairs between 1) nulliparas and 6 week primiparas, 2) 6 week and 6 month primipara pairs, and 3) three age/race groups using test of two proportions and one-way anova.Results: Initial review indicated only 3 subjects not of African-American (AA) or Caucasian (W) race, and only 1 AA primipara of age ≥30yrs, therefore statistical analysis was limited to 45 primiparas and 25 nulliparas. Incidence of any abnormality at any of the 4 sites was considered abnormal. Frequency of abnormal muscle by race and age is shown in the In those subjects recovering to normal MR by 6 months, an average of nearly 60% increase in R puborectalis muscle thickness compared to that seen at 6 weeks indicated the extent of the injury. Subjects with injury to both the puborectalis and ileococcygeous at 6 weeks did not recover to normal at 6 months, whereas those with injury only to the puborectalis tended to have normal MR at 6 months. Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. NIH Public AccessAuthor Manuscript Conclusions: Nulliparity did not guarantee a normal assessment of levator ani anatomy by our blinded reader, and frequency of injury in this series is somewhat greater than that previously reported for primiparas. Younger Caucasian primiparas had a better recovery at 6 months than older Caucasians. Subjects experiencing more global injury, in particular to the ileococcygeous, tended not to recover muscle bulk.

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Section: Introductionmentioning

confidence: 99%

Levator ani abnormality 6 weeks after delivery persists at 6 months

Branham

Thomas

Jaffe

et al. 2007

American Journal of Obstetrics and Gynecology

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“…It is postulated that this effect is augmented with repeated pregnancies (Shafik and El-Sibai 2002). However, Lien et al (2005) reported that the pudendal nerve is injured during vaginal delivery but not during pregnancy. Animal models simulating the childbirth trauma with vaginal distension in rat support this hypothesis (Lin et al 1998;Damaser et al 2003).…”

Section: Discussionmentioning

confidence: 99%

Impaired Function of the Levator Ani Muscle in the Grand Multipara and Great Grand Multipara

Kişli

Kisli

Ağargün

et al. 2006

Tohoku J. Exp. Med.

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Repeated deliveries might disturb the levator function and increase defecation disorders. In this prospective study, we determined the electric activity of the levator ani muscle (LAM) in nullipara, multipara, grand multipara, and great grand multipara (20 subjects for each group). Multiparity, grand multiparity, and great grand multiparity were defined as women having 2 -5, 6 -9, and 10 and over deliveries, respectively. The number of deliveries of multipara, grand multipara and great grand multipara were 4.05 ± 1.14 (2 -5), 7.55 ± 1.23 (6 -9) and 12.2 ± 2.16 (10 -17), respectively. All women were asked whether they had experienced constipation, fecal or urinary incontinence, and/or pelvic pain. All women were also evaluated for pelvic organ prolapse. Electromyography (EMG) of the LAM at rest and on contraction was recorded. EMG is an electrical recording of muscle activity. Constipation, incontinence and pelvic organ prolapse were encountered in multipara, grandmultipara and great grand multipara women. The LAM EMG at rest and on contraction in the nullipara was accepted as control. Both the resting and contractile activities of the LAM were as follows: nullipara > multipara > grand multipara > great grand multipara. These findings indicate that levator dysfunction and defecation disorders are increased with repeated deliveries because of pudendal and/or levator ani nerve injury and traumatic injury to the LAM occurred with the mechanical stresses of vaginal deliveries.

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“…In our sample there are 4 professional cyclists, which make up 7.5% of the cases. There are gynecological-obstetrics causes such as, vaginal partum, episiotomy, pelvic and vaginal surgery [8][9][10], in which a higher incidence of PNES has been observed. In our series there were 33.3% of women with a gynecological history.…”

Section: Discussionmentioning

confidence: 99%

“…Causes associated with this entrapment are: professional/ sports activities that involve the sitting position [5,6], perineal injuries [7], gynecological causes [8][9][10], pelvis radiotherapy, rectal prolapse [11][12][13].…”

Section: Introductionmentioning

confidence: 99%