Correlation between levator ani muscle injury and pelvic organ prolapse in primiparous women 6 months post vaginal delivery：a static and dynamic MRI study
10.3760/cma.j.issn.1005-1201.2016.01.007
- VernacularTitle:静态及动态MRI评价初产妇经阴道分娩后6个月肛提肌损伤与盆腔器官脱垂的关系
- Author:
Na LI
;
Yue CHENG
;
Can CUI
;
Wen SHEN
- Publication Type:Journal Article
- Keywords:
Parturition;
Magnetic resonance imaging;
Pelvic organ prolapse
- From:
Chinese Journal of Radiology
2016;(1):27-31
- CountryChina
- Language:Chinese
-
Abstract:
Objective To observe the location of pelvic organs, the morphology and function of levator ani muscle (LAM) in primiparous women post vaginal delivery at 6 months postpartum using static and dynamic MRI, and investigate the correlation between LAM injury and pelvic organ prolapse (POP). Methods A perspective analysis of static and dynamic MRI was performed in fifty-one primiparous women post vaginal delivery at 6 months postpartum and thirty-five nulliparous women without experience of pregnancy and delivery as control group from June 2014 to January 2015. Previous pregnancy and abortion history, previous pelvic surgery and pelvic mass diseases were excluded. Cases with pelvic floor dysfunction symptoms were excluded from the control group. All of the women underwent static and dynamic MRI. The primiparous group was divided into two groups on presence or absence of POP on MRI findings:primiparous POP group and primiparous control group. The levatorani scoring system based on static MRI was used to characterize morphological changes of LAM into none, minor and major injury by the total score of bilateral LAM. A series of parameters including H line (the distance between the inferior margin of pubic symphysis to anorectal junction), M line (the perpendicular distance between the distal end of H line to pubococcygeal line), levator plate angle (LPA), iliococcygeal angle (ICA), and levator hiatus length and area were measured on static and dynamic MR images. Fisher exact test was performed to compare difference in distribution of the LAM injury between the primiparous group and control group, as well as the primiparous POP group and primiparous control group. Independent sample t test or Mann-Whitney test was used to compare difference in LAM parameters between the primiparous POP group and primiparous control group. Results In the 51 cases primiparous group, 44 cases showed none injury, whilst 5 cases with minor and 2 cases with major injury in the puborectal muscle. Thirty two cases showed none injury, whilst 10 cases with minor and 9 cases with major injury in the iliococcygeal muscle. In the 35 cases control group, none injury was shown in puborectal muscle, whilst 32 cases with none, 2 cases with minor and 1 case with major injury in the iliococcygeal muscle. There was no significant difference in the puborectal muscle injury between the two groups (P=0.203), and there was significant difference in the iliococcygeal muscle injury between the two groups (P<0.05). In the 24 cases primiparous POP group, 20 cases showed none injury, whilst 2 cases with minor and 2 cases with major injury in the puborectal muscle. Fourteen cases showed none injury, whilst 6 cases with minor and 4 cases with major injury in the iliococcygeal muscle. In the 27 cases primiparous control group, 24 cases showed none and 3 cases with minor injury in the puborectal muscle, whilst 18 cases with none, 4 cases with minor and 5 cases with major injury in the iliococcygeal muscle. There was no significant difference in the puborectal muscle injury and iliococcygeal muscle injury between the two groups (P=0.588 and 0.559, respectively). The LH during Valsalva status in primiparous POP group and primiparous control group were (6.7 ± 1.1) and (5.0 ± 0.6) cm, respectively, whilst the LHA was (41.6 ± 12.6) and (24.2 ± 5.5) cm2. There were significant difference between the corresponding groups (P=0.042 and 0.004, respectively). There was no significant difference between the corresponding groups of the other LAM parameters on static and dynamic MRI (all P>0.05). Conclusion Vaginal delivery may cause various degrees of LAM injury, the LAM functional deficiency were observed in primiparous women combined with POP.
