不同分娩方式对生殖裂孔形态和肛提肌功能的影响

目的：探讨不同分娩方式对生殖裂孔形态和肛提肌功能的影响。方法：选取2009年8月-2009年12月在广州医学院第一附属医院产科分娩的初产妇32例，其中选择性剖宫产21例，阴道自然分娩11例，同期选择健康未生育妇女13例为对照组。前两组均在产后12周选择3种不同状态下（静态、Valsalva动作时及肛提肌最大收缩状态），采用会阴三维超声检测生殖裂孔的直径（LHD）、前后径（LHAP）、横径（LHLR）、周长（LHC）及尿道中点至肛提肌的距离（LUG），计算肛提肌弹性econt，阴道指诊评估肛提肌收缩时的肌力。结果：选择性剖宫产组、阴道自然分娩组分别与对照组比较，生殖裂孔各径线超声检测结果均大于对照组，肛提肌肌力和肛提肌弹性小于对照组（均P〈0．05）。选择性剖宫产组与阴道自然分娩组比较，会阴超声检测生殖裂孔的LHD、LHAP、LHLR、LHC、LUG，肛提肌弹性等差异3组均无统计学（P〉0．05），但肛提肌肌力等级较阴道自然分娩组高（P〈0．05）。结论：选择性剖宫产和阴道自然分娩者产后均存在生殖裂孔形态学变化，提示妊娠及分娩均存肛提肌损伤，选择性剖宫产对盆底保护作用有限．

A pilot study on impacts of different delivery modes on morphology of levator hiatus and function of levator ani muscle

Objective ：To investigate the impacts of different delivery modes on morphology of levator hiatus and function of levator ani muscle. Methods： 32 primiparas registered to the Obstetrics Department of First Affiliated Hospital, Guangzhou Medical College, between August and December 2009, were recruited. The subjects included 21 cases of selective caesarean section and 11 of vaginal delivery. A contemporary cohort of 13 healthy nulliparas with matched age, height, body mass index was selected as control group. The primipara and control groups were measured for diameter of the levator hiatus（LHD）, anteroposterior diameter of levator hiatus （ LHAP）, transverse diameter of levator hiatus （ LHLR）, circumference of levator hiatus （ LHC ） and the distance from the mid-point of urethra to the medial margin transperineal ultrasound under three different states （ at of levator ani muscles （LUG） by three-dimensional rest, Valsalva action and levator ani muscle maximum contraction）. The elasticity of levator ani muscle was then calculated,and the contraction strength of levator ani muscle was evaluated by vaginal palpation. Results：Subjects with selective caesarean section or vaginal delivery showed greater dimensional parameters of the levator hiatus （ as measured by three-dimensional transperineal ultrasound） ,lowered elasticity and contraction strength of levator ani muscle as compared with the control group （P 〈 0.01 ）. The LHD, LHAP, LHLR, LHC and LUG of levator hiatus and the levator ani muscle elasticity in the selective caesarean section group did not differ from those in the vaginal delivery group （ P 〉 0.05 ）, but the levator ani muscle strength was stronger in selective caesarean section group （ P 〈 0.05 ）. Conclusions ： Altered morphology of the levator hiatus may be detected either in women after selective caesarean section or vaginal delivery, suggesting that both pregnancy and delivery may cause injury to the levator ani muscle, and that selective cesarean section provides only limited protection for the pelvic floor.