Regular paperThe appearance of levator ani muscle abnormalities in magnetic resonance images after vaginal delivery☆
Section snippets
Materials and methods
Magnetic resonance images of the pelvis were obtained from 240 women as part of an institutional review board–approved study concerning vaginal delivery and stress urinary incontinence. Multiplanar two-dimensional fast spin (echo time 15 ms, repetition time 4000 ms) proton density magnetic resonance images of all pelves were obtained by use of a 1.5-tesla superconducting magnet (Signa; General Electric Medical Systems, Milwaukee, WI) with version 5.4 software as previously described.1 Images 5
Results
There were 32 women (20%) with a visible defect in one or both levator ani muscles among the 160 parous women in the study. Of these, 29 (18%) involved the pubovisceral portion of the muscle and three (2%) involved the iliococcygeal portion. Of the 80 women who were incontinent, 23 (28%) had a defect in the levator ani muscle, and of the 80 primiparous continent women, nine (11%) had a defect, making stress incontinent primiparas twice as likely to have a muscle abnormality. No defects were
Discussion
Abnormalities have previously been demonstrated in the levator ani muscles of women with stress urinary incontinence7 and pelvic organ prolapse,8 using magnetic resonance imaging (MRI). These abnormalities could be a variant of normal anatomy, they could be a distortion caused by abnormal pelvic organ positions, or they could be damage that occurred during vaginal delivery. Our study depicts levator ani muscle damage after vaginal birth and provides the first scientific evidence that supports
References (25)
- et al.
A structured system to evaluate urethral support anatomy in magnetic resonance images
Am J Obstet Gynecol
(2001) - et al.
Mag-netic resonance imaging of the levator ani with anatomic correlation
Obstet Gynecol
(1996) - et al.
The standardization of terminology of female pelvic organ prolapse and pelvic floor dysfunction
Am J Obstet Gynecol
(1996) - et al.
On-screen vector based ultrasound assessment of vesical neck movement
Am J Obstet Gynecol
(2001) - et al.
Two- and 3-dimensional MRI comparison of levator ani structure, volume, and integrity in women with stress incontinence and prolapse
Am J Obstet Gynecol
(2001) - et al.
MR imaging of levator ani muscle recovery following vaginal delivery
Int Urogynecol J
(1999) Pelvic anatomy I. Pelvic floor muscles
Ann R Coll Surg Engl
(1974)- et al.
The contribution of magnetic resonance imaging of the pelvic floor to the understanding of urinary incontinence
Br J Urol
(1993) - et al.
Static magnetic resonance imaging of the pelvic floor muscle morphology in women with stress urinary incontinence and pelvic prolapse
Neurourol Urodyn
(1998) - et al.
Epidemiology of genital prolapseObservations from the Oxford Family Planning Association study
Br J Obstet Gynaecol
(1997)
Factors associated with risk of stress urinary incontinence in women
Nurs Res
The symptom of stress incontinence caused by pregnancy or delivery in primiparas
Obstet Gynecol
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Supported by National Institutes of Health grants R01 DK51405 and R01 HD38665.