Alteration of pelvic floor biometry in different modes of delivery
Abstract
Objective: The objective of this study is to investigate and compare the effects of different modes of delivery on bladder neck mobility, anorectal angle and levator hiatus distensibility detected by ultrasound assessment.
Methods: Two hundreds nulliparous women were divided into two groups based on their type of delivery, vaginal delivery (VD) group and cesarean section (CS) group. The biometry of pelvic floor, including bladder neck mobility, anorectal angle and levator hiatus distensibility, in both groups of women was observed and compared at 6-8 weeks after delivery by perineal ultrasound assessment.
Results: On valsalva, the bladder neck mobility in the VD group was significantly increase, when compared with CS group (P<0.05). However, here was no significant difference between two groups at rest. The anorectal angle (ARA) was no significant differences between two groups at rest and on valsalva. Compared with the CS group, transverse diameters (LR), anteroposterior (AP) and levator hiatal area (LHA) of levator hiatus in VD group were significantly increased at rest and on valsalva (P<0.05)
Conclusion: Perineal ultrasound can objectively and movably detect pelvic floor dysfunction of women after different modes of delivery, and a normal VD may be a risk factor for pelvic floor dysfunction.
Keywords
Download Options
Introduction
Pelvic floor dysfunction (PFD) occurring in women comprises a board range of clinical scenarios such as lower urinary tract excretory and defecation disorders because of urinary and anal incontinence, overactive bladder, pelvic organ prolapsed as well as sexual disorders. [1] In developing countries, the prevalence of pelvic organ prolapse, urinary and fecal incontinence is 19.7%, 28.7%, and 6.9%, respectively. Pelvic organ prolapse is also a major health problem in developed countries. [2] It is estimated that women have a 12% lifetime risk (by age 80) of undergoing surgical treatment for urinary incontinence or prolapse. [3, 4] At least 11% of women require surgery for pelvic floor disorder. [5]
Age, ethnicity, multiparty, mode of delivery, history of pelvic surgery, pregnancy, chronic cough, obesity, spinal cord disorders, family history, and genetics are the most common identifiable risk factors for the development of PFD. [6] Reported pregnancy-related risk factors include pregestational body mass index (BMI). The other risk factors include past histories of previous lower abdominal surgeries such as laparoscopic and hysteroscopic procedures, uterine curettage, and urinary incontinence surgery. [7]
Pregnancy and childbirth are the cause of PFD including increase in urethral and pelvic organ mobility, hiatal distension, and levator ani muscle (LAM) injury. [8] It is believed that the strain of the gravid uterus and hormonal changes during pregnancy lead to connective tissue remodeling and disruption of normal pelvic floor function. During vaginal delivery, injury to the puborectal fascicle of the levator ani muscle may occurs, and it may be an etiological factor for uterine prolapsed, cystocele and rectocele. [9, 10] Furthermore, distension of the levator ani, ranged 25-245%, allows the hiatus to widen during crowning of the fetal head, resulting in marcoscopically visible [11] and microscopic/ultra structural[12] damage to the puborectal fascicle of the levator ani muscle[13]. Thus, the orphological changes of levator hiatus have clinical significance in the subsequent development of PFD. The enlargement of hiatus is more obvious especially after levator ani avulsion.
Conclusion
1. Changes in the levator ani muscle postdelivery are easily demonstrable on pelvic floor 3D ultrasonography.
2. The hiatal dimensions in VD group were larger than those in CS group at rest and on valsalva maneuver.
3. Pregnancy itself is the most important and independent risk factor for PDF. The women with PDF after delivery need rehabilitative treatment.