Krankenhaus Barmherzige Brüder-Frauenklinik St. Hedwig, Department of Obstetrics and Gynecology, University of Regensburg, Regensburg, Germany.
Ultrasound Obstet Gynecol. 2010 May;35(5):583-8. doi: 10.1002/uog.7563.
Morphological changes of the pelvic floor during pregnancy and delivery can be visualized by three-dimensional (3D) perineal ultrasound. The aim of this study was to compare biometric measurements of the levator ani muscle according to maternal constitutional factors, delivery mode and size of the baby immediately after the first delivery.
In this prospective observational study, 130 primiparae were recruited (all of them Caucasians with singleton pregnancy and cephalic presentation). A 3D perineal ultrasound scan was performed on the second day after delivery with standardized settings. Volumes were obtained at rest and on Valsalva maneuver, and biometric measurements of the levator hiatus were determined in the axial plane. Different obstetric and constitutional parameters were obtained from our clinical files.
All biometric measurements of the levator hiatus were significantly greater in the vaginal delivery group than in the Cesarean section group (P < 0.001), whereas subgroup analysis within the vaginal (spontaneous vs. operative vaginal) and Cesarean (primary vs. secondary) delivery groups did not show statistically significant differences. There was no demonstrable influence of maternal constitutional factors (age, body mass index (BMI)) or different obstetric parameters (length of second stage of labor, episiotomy, maternal injuries) on levator hiatus size postpartum, even in subgroups that delivered vaginally. Women with de novo postpartum stress incontinence showed a significantly higher mean levator hiatus transverse diameter and larger hiatal area on Valsalva maneuver (P < 0.05). There was also a positive but very weak correlation between the newborn's head circumference and hiatal dimensions at Valsalva maneuver (P < 0.05).
Pelvic floor imaging by 3D ultrasound is easily accessible even on the first days after delivery and can provide useful information on morphological changes of the levator ani muscle. In our study, women with vaginal or operative vaginal delivery had a significantly larger hiatal area and transverse diameter than women who delivered by Cesarean section. Maternal constitutional factors (BMI, age) and duration of second stage of labor had no influence on the biometric measurements of hiatal area, whereas weight and head circumference of the baby showed a positive correlation with area of the levator hiatus.
三维（3D）会阴超声能显示妊娠和分娩期间盆底的形态变化。本研究的目的是比较初次分娩后即刻，根据产妇体质因素、分娩方式和婴儿大小，对肛提肌的生物测量值进行比较。
本前瞻性观察研究纳入了 130 例初产妇（均为白人，单胎妊娠，头位）。在分娩后第二天使用标准化设置进行 3D 会阴超声检查。在休息和valsalva 动作时获得体积，并在轴平面上测量肛提肌裂孔的生物测量值。从我们的临床档案中获得了不同的产科和体质参数。
阴道分娩组的所有肛提肌裂孔的生物测量值均显著大于剖宫产组（P<0.001），而阴道分娩（自然 vs 产道助产）和剖宫产（初次 vs 再次）亚组分析中，差异无统计学意义。产妇体质因素（年龄、体重指数（BMI））或不同产科参数（第二产程长度、会阴切开术、产妇损伤）对产后肛提肌裂孔大小无明显影响，即使是阴道分娩的亚组也是如此。新发产后压力性尿失禁的女性在valsalva 动作时的平均肛提肌横向直径和裂孔面积明显较大（P<0.05）。新生儿头围与valsalva 动作时裂孔尺寸也存在正相关，但相关性非常弱（P<0.05）。
即使在分娩后最初几天，3D 超声对盆底的成像也很容易获得，并且可以提供有关肛提肌形态变化的有用信息。在我们的研究中，阴道分娩或产道助产的女性的裂孔面积明显大于剖宫产的女性。产妇体质因素（BMI、年龄）和第二产程时间对裂孔面积的生物测量值没有影响，而婴儿的体重和头围与肛提肌裂孔的面积呈正相关。
