Correlation between levator ani muscle injuries on magnetic resonance imaging and fecal incontinence, pelvic organ prolapse, and urinary incontinence in primiparous women

doi:10.1016/j.ajog.2010.01.002

American Journal of Obstetrics and Gynecology

Volume 202, Issue 5, May 2010, Pages 488.e1-488.e6

Presented at the 30th Annual Scientific Meeting of the American Urogynecologic Society, Hollywood, FL, Sept. 24-26, 2009, and the 95th Scientific Assembly and Annual Meeting of the Radiologic Society of North America, Chicago, IL, Nov. 29-Dec. 4, 2009.

https://doi.org/10.1016/j.ajog.2010.01.002 Get rights and content

Objective

The objective of the study was to correlate the presence of major levator ani muscle (LAM) injuries on magnetic resonance imaging (MRI) with fecal incontinence (FI), pelvic organ prolapse (POP), and urinary incontinence (UI) in primiparous women 6-12 months postpartum.

Study Design

A published scoring system was used to characterize LAM injuries on MRI dichotomously (MRI negative, no/mild vs MRI positive, major).

Results

Major LAM injuries were observed in 17 of 89 (19.1%) women who delivered vaginally with external anal sphincter (EAS) injuries, 3 of 88 (3.5%) who delivered vaginally without EAS injury, and 0 of 29 (0%) who delivered by cesarean section before labor (P = .0005). Among women with EAS injuries, those with major LAM injuries trended toward more FI, 35.3% vs 16.7% (P = .10) and POP, 35.3% vs 15.5% (P = .09), but not UI (P = 1.0).

Conclusion

These data support the growing body of literature suggesting that both EAS and LAM are important for fecal continence and that multiple injuries contribute to pelvic floor dysfunction.

Section snippets

Study population

The CAPS study was a multicenter, prospective cohort study conducted by the Pelvic Floor Disorders Network (PFDN) and supported by the National Institute of Child Health and Human Development. This study of primiparous women evaluated FI and UI symptoms at 6 weeks and 6 months after delivery as has been previously described.5, 6, 7 The CAPS study included 3 cohorts of primiparous women: group 1, vaginal delivery with a clinically recognized third- or fourth-degree anal sphincter tear (sphincter

Population

The population has been previously described.⁸ Briefly, the mean age and SD across all cohorts is 27.8 ± 6.1, with no significant difference in age by cohort (P = .30). Approximately 75% of the population was white. Fifty-six percent of the sphincter tear group had undergone a forceps or vacuum delivery, compared with 11% of the vaginal control group. Additionally, the birthweight was significantly larger in the sphincter tear group as compared with the vaginal control group or cesarean control

Comment

Six to 12 months after delivery, major LAM injuries were significantly more common in women with sphincter tears than in those who delivered vaginally without sphincter tears or by cesarean. One in 5 women with a sphincter tear had a major LAM injury on MRI. We found no major LAM injuries in women who delivered by cesarean without labor. Our findings are consistent with a study using endoanal MRI in 105 women with severe FI, which found that LAM defects coexisted with anal sphincter defects in

Conclusion

A higher prevalence of major LAM injury is identified on MRI in women who experience anal sphincter tears during delivery. This study confirms a reliable image scoring system for assessing these LAM injuries on MRI. It is likely that the combination of anal sphincter injuries during delivery and major LAM injury increases the future risk of POP and FI. Patients with such a history may benefit from early surveillance, education, and therapy directed at preventing the later sequelae of pelvic

References (20)

J.O. DeLancey et al.
The appearance of levator ani muscle abnormalities in magnetic resonance images after vaginal delivery
Obstet Gynecol
(2003)
J.O. DeLancey et al.
Stress urinary incontinence: relative importance of urethral support and urethral closure pressure
J Urol
(2008)
R.C. Bump et al.
The standardization of terminology of female pelvic organ prolapse and pelvic floor dysfunction
Am J Obstet Gynecol
(1996)
S.E. Swift et al.
Correlation of symptoms with degree of pelvic organ support in a general population of women: what is pelvic organ prolapse?
Am J Obstet Gynecol
(2003)
A.R. Feinstein et al.
High agreement but low kappa: I. The problems of two paradoxes
J Clin Epidemiol
(1990)
R. Kearney et al.
Obstetric factors associated with levator ani muscle injury after vaginal birth
Obstet Gynecol
(2006)
K.L. Shek et al.
The effect of childbirth on hiatal dimensions
Obstet Gynecol
(2009)
V.L. Handa et al.
Magnetic resonance assessment of pelvic anatomy and pelvic floor disorders after childbirth
Int Urogynecol J Pelvic Floor Dysfunct
(2009)
D. Borello-France et al.
Fecal and urinary incontinence in primiparous women
Obstet Gynecol
(2006)
H.E. Richter et al.
Endoanal ultrasound findings and fecal incontinence symptoms in women with and without recognized anal sphincter tears
Obstet Gynecol
(2006)

There are more references available in the full text version of this article.

Cited by (109)

Obstetric risk factors for levator ani muscle avulsion: A systematic review and meta-analysis
2024, European Journal of Obstetrics and Gynecology and Reproductive Biology
Women have a 11% lifetime risk of undergoing surgery for vaginal prolapse. Levator ani muscle (LAM) avulsion is one etiological factor associated with primary and recurrent pelvic organ prolapse. Pelvic organ prolapse has been shown to greatly affect the quality of life and well-being of women. Conduct a meta-analysis identifying risk factors associated with LAM avulsion recognised on transperineal ultrasound (TPUS) or magnetic resonance imaging (MRI) in primiparous women after vaginal birth.
OVID Medline, Embase and the Cochrane Library from inception to January 2021 were searched. Review Manager 5.3 (The Cochrane Collaboration) was used to analyse data. Odds ratios (OR) with 95% confidence intervals (95% CIs) were calculated. The heterogeneity among studies was calculated using the I² statistic.
Twenty-five studies were eligible for inclusion (n = 9333 women). Major LAM avulsion was diagnosed in an average of 22 % (range 12.7–39.5 %) of cases. Twenty-two studies used TPUS and three used MRI to diagnose avulsion. Modifiable and non-modifiable risk factors were identified. Significant predictors identified were forceps (OR 6.25 [4.33 – 9.0]), obstetric anal sphincter injuries (OR 3.93 [2.85–5.42]), vacuum (OR 2.41 [1.40–4.16]), and maternal age (OR 1.06 [1.02–1.10]).
This is the first meta-analysis of both modifiable and non-modifiable risk factors associated with LAM avulsion. This information could be used to develop a clinically applicable risk prediction model to target postnatal women at risk of LAM avulsion with a view to prevent the onset of pelvic floor organ prolapse.
Chinese expert consensus on primary prevention for pelvic floor dysfunction during pregnancy
2023, Gynecology and Obstetrics Clinical Medicine
Pregnancy has been identified as a risk factor for pelvic floor dysfunction (PFD). The aim of this study was to establish primary prevention measures for PFD during pregnancy and reduce the overall incidence of PFD.
We assembled a panel of 36 experts, including gynecologists, obstetricians, and physiotherapists. Through surveys and expert meetings, the panel reviewed and assessed the safety and effectiveness of various clinical interventions. Based on expert comments from Round 1, a revised list of 8 clinical interventions was developed and submitted for a second round of expert review.
A consensus was reached on the importance of implementing prevention measures to protect pelvic floor function during pregnancy. Experts particularly emphasized the significance of health education, weight management, pelvic floor muscle training, respiratory training, overall exercise, physical activity, and perineal massage.
The expert consensus provides comprehensive clinical measures to safeguard pelvic floor function during pregnancy. This paper represents the initial step toward developing scientific recommendations for pregnant women regarding the primary prevention of PFD. Future research should focus on the implementation of these recommendations in clinical practice.
Diagnosis of maternal birth trauma by pelvic floor ultrasound
2023, European Journal of Obstetrics and Gynecology and Reproductive Biology
Brief Summary: Maternal somatic birth trauma due to vaginal delivery is more common than generally assumed and an important cause of future morbidity.
Maternal birth trauma may involve both psychological and somatic morbidity, some of it long-term and permanent. Somatic birth trauma is now understood to encompass not just episiotomy, perineal tears and obstetric anal sphincter injuries (OASI), but also trauma to the levator ani muscle, termed ‘avulsion’. This review will focus on recent developments in the imaging diagnosis of maternal birth trauma, discuss the most important risk factors and strategies for primary and secondary prevention.
Translabial and exo-anal ultrasound allow the assessment of maternal birth trauma in routine clinical practice and enable the use of levator avulsion and anal sphincter trauma as key performance indicators of maternity services. This is likely to lead to a greater awareness of maternal birth trauma amongst maternity caregivers and improved outcomes for patients, not the least due to an increasing emphasis on patient autonomy and informed consent in antenatal and intrapartum care.
Impact of obstetric lesions of the levator ani on anal continence
2022, Progres en Urologie
L’accouchement par voie basse induit des lésions musculaires à type d’avulsion et étirement mineur du levator ani (LA). Partageant les mêmes facteurs de risque que les lésions obstétricales du sphincter anal (LOSA), elles peuvent être concomitantes. Les LOSA sont le 1^er facteur de risque d’incontinence anale (IA) chez la femme. Le rôle des lésions lévatoriennes dans la genèse de l’IA est controversé.
Il s’agit d’une revue systématique sans méta-analyse ayant pour objectif de préciser l’impact des lésions du LA sur la continence anale.
Selon les recommandations PRISMA, réalisation d’une recherche bibliographique (2000–2022) sur PubMed avec les mots clés : « levator ani » « anal incontinence » « obstetric trauma » et sur Science Direct avec les mots clés « levator ani », « avulsion », « anal incontinence ». Cent-soixante-dix articles ont été identifiés, 16 ont été retenus. Le niveau de preuve a été déterminé en utilisant la Newcastle Ottawa Scale.
Selon les différents auteurs, la prévalence d’avulsion variait de 15 % à 32,2 % parmi les femmes ayant accouché par voie basse, les femmes présentant des lésions du LA présentaient plus de LOSA (29,4 % à 37,5 % des patientes ayant des LOSA avaient une lésion du LA). Pour l’IA, les avulsions du LA ne sont pas un facteur de risque indépendant mais sont, en présence de LOSA, un facteur aggravant (OR, 23,3, 95 % IC, 2,0–267,6). Les doubles lésions seraient plus à risque d’IA à long terme (p < 0,001).
Les lésions du LA ne sont pas un facteur indépendant d’IA, bien que leur prévalence soit plus élevée dans la population des femmes incontinentes anales ; elles sont plus fréquentes chez les femmes présentant des LOSA et dans cette population, elles sont un facteur aggravant de l’IA et un facteur de risque d’IA à long terme.
Vaginal delivery induces avulsion type muscle lesions and minor stretching of the levator ani muscle (LAM). Sharing the same risk factors as obstetric anal sphincter injury (OASIS), they can be concomitant. OASIS are the first risk factor for anal incontinence (AI) in women. The role of levatorian lesions in the genesis of AI is controversial.
This is a systematic review without meta-analysis aimed at clarifying the impact of LA lesions on anal continence.
According to PRISMA recommendations, carrying out a bibliographic search (2000–2022) on PubMed with the keywords: “levator ani” “anal incontinence” “obstetric trauma” and on Science Direct with the keywords “levator ani”, “avulsion”, “anal incontinence”. One hundred and eighty articles were identified, 16 were selected.. The level of evidence was determined using the Newcastle Ottawa Scale.
According to the different authors, the prevalence of avulsion varied from 15% to 32.2% among women who gave birth vaginally, women with LA lesions presented more LOSA (29.4% to 37.5% of patients with OASIS also had an LA lesion). For AI, LA avulsions are not an independent risk factor but are, in the presence of OASIS, an aggravating factor (OR, 23.3, 95% CI, 2.0–267.6). Double lesions would be at greater risk of long-term AI (P < 0.001).
LA lesions are not an independent factor of AI, although their prevalence is higher in the population of anal incontinent women; they are more frequent in women with OASIS and in this population, they are an aggravating factor for AI and a risk factor for long-term AI.
A review of levator ani avulsion after childbirth: Incidence, imaging and management
2022, Midwifery
Key Content
• Levator ani muscle (LAM) avulsion injury occurs occultly during childbirth, most commonly during operative vaginal deliveries.
• Injuries of levator ani have long term sequelae for pelvic floor health. As life expectancy increases the burden of disease upon urogynaecology services will need to be considered.
• Diagnosis of this condition can be difficult as there is no agreed ‘gold standard’ imaging modality.
• There is no consensus regarding surgical management of LAM avulsion.
Learning objectives
• Review anatomy and function of levator ani muscle
• Identify the risk factors for levator ani avulsion injury
• Role of imaging to appropriately identify LAM injury and current management options including appropriate follow up
• Management of subsequent pregnancy following LAM avulsion
Ethical issues
• Is there value to the patient in diagnosing levator ani avulsion when there is no recommended treatment for these injuries?
Impact of pushing timing on occult injury of levator ani: secondary analysis of a randomized trial
2022, American Journal of Obstetrics and Gynecology
Evidence of detachment of the levator ani muscle system is seen more frequently in patients with pelvic floor disorders. It has been suggested that passive descent of the fetus before pushing could be used to decrease operative vaginal delivery and levator ani muscle injury.
This planned analysis aimed to determine whether immediate or delayed pushing was associated with an increased proportion of injury to the levator ani muscle system after the first delivery among nulliparous women.
The Optimizing Management of the Second Stage study was a multicenter randomized trial. Nulliparous women with term pregnancies and neuraxial analgesia were randomly assigned at complete cervical dilation to either immediate pushing or delayed pushing for 1 hour. A subset of participants consented to longitudinal objective pelvic floor assessments: (1) during postpartum stay (initial), (2) at 6 weeks (postpartum 1), and (3) at 6 months (postpartum 2) with transperineal 3-dimensional ultrasound. Following the completion of all visits by all subjects, saved 3-dimensional ultrasound volumes were assessed in a masked fashion. The outcome was “occult” levator ani muscle injury on the right or left, defined as a widening of the attachment of the levator ani to its origin utilizing the levator-urethra gap measurement. Measurements and proportions were compared between the 2 groups by study visit using the χ² test or Fisher exact test for categorical variables and the t test or Mann-Whitney U test for continuous variables as appropriate.
Here, 941 of 2414 randomized subjects (39.0%) participated in the pelvic floor assessments: 452 in the immediate pushing group and 489 in the delayed pushing group. We obtained sonograms on 67%, 83%, and 77% of the pelvic floor assessment participants at the initial, postpartum 1, and postpartum-2 visits, respectively. Demographic and labor characteristics were comparable between the 2 groups; 94% of participants were non-Hispanic, and 50% of participants were Black. Levator ani muscle injury was noted in 77 participants (13.6%) at the initial visit, 99 (13.1%) at PP1, and 72 (10.6%) at PP2. There was no difference in injury between women in the immediate pushing group and women in the delayed pushing group. These findings did not change when the threshold (sensitivity) of levator ani muscle injury was adjusted to a less conservative measure.
Among nulliparous women at term with neuraxial analgesia, the rates of occult levator ani muscle injury were not different between women undergoing immediate pushing and women undergoing delayed pushing in the second stage of labor. Further research efforts are needed to understand the development and potential prevention of subsequent pelvic floor disorders.

View all citing articles on Scopus

: Cite this article as: Heilbrun ME, Nygaard IE, Lockhart ME, et al. Correlation between levator ani muscle injuries on magnetic resonance imaging and fecal incontinence, pelvic organ prolapse, and urinary incontinence in primiparous women. Am J Obstet Gynecol 2010;202:488.e1-6.

: Reprints not available from the authors.

: Supported by Grants (U01 HD41249, U10 HD41268, U10 HD41248, U10 HD41250, U10 HD41261, U10 HD41263, U10 HD41269, and U10 HD41267) from the Eunice Kennedy Shriver National Institute of Child Health and Human Development and the Office of Research on Women's Health.

View full text

Meeting paperAUGS paperCorrelation between levator ani muscle injuries on magnetic resonance imaging and fecal incontinence, pelvic organ prolapse, and urinary incontinence in primiparous women

Objective

Study Design

Results

Conclusion

Section snippets

Study population

Population

Comment

Conclusion

Obstet Gynecol

J Urol

Am J Obstet Gynecol

Am J Obstet Gynecol

J Clin Epidemiol

Obstetric factors associated with levator ani muscle injury after vaginal birth

Obstet Gynecol

The effect of childbirth on hiatal dimensions

Obstet Gynecol

Magnetic resonance assessment of pelvic anatomy and pelvic floor disorders after childbirth

Int Urogynecol J Pelvic Floor Dysfunct

Fecal and urinary incontinence in primiparous women

Obstet Gynecol

Endoanal ultrasound findings and fecal incontinence symptoms in women with and without recognized anal sphincter tears

Obstet Gynecol

Meeting paper
AUGS paper
Correlation between levator ani muscle injuries on magnetic resonance imaging and fecal incontinence, pelvic organ prolapse, and urinary incontinence in primiparous women