Lin Xiaonan, Chen Jinming, Pan Haijing, Xu Yaye, Zhong Qun, Lin Xueying, Ye Chengbin
Department of Radiology, The Affiliated People's Hospital of Fujian University of Traditional Chinese Medicine, 602 Ba Yi Qi Zhong Road, Fuzhou, China.
Department of Ultrasound, Fujian Medical University Union Hospital, 29 Xinquan Road, Fuzhou City, Fujian Province, China.
BMC Pregnancy Childbirth. 2025 Jan 24;25(1):62. doi: 10.1186/s12884-025-07198-8.
Vaginal childbirth is one of the main risk factors for pelvic floor dysfunction. Magnetic resonance imaging (MRI) can facilitate quantitative evaluation of the morphology and function of the pelvic floor in static and dynamic environments. The objective of this study was to investigate the changes in pelvic floor morphology and function in primigravida women before pregnancy (BP) and after vaginal delivery.
Primigravida women underwent pelvic floor MRI scans BP, at 3 months postpartum (3mPP), and at 6 months postpartum (6mPP). Various pelvic floor MRI data were measured, including the obturator internus muscle (OIM) area, anterior pelvic area, puborectalis muscle thickness (PRT), levator plate angle (LPA), iliococcygeal angle, bladder-pubococcygeal line (B-PCL), uterus-pubococcygeal line (U-PCL), puborectal hiatus line, muscular pelvic floor relaxation line, levator hiatus area, urethral mobility, bladder neck descent, and cervix descent.
In the resting state, the OIM area and PRT decreased whereas the anterior pelvic area increased from BP to 3mPP. During the straining maneuver, all parameters except U-PCL and urethral mobility showed statistically significant differences (P < 0.05). The OIM area and PRT increased whereas the anterior pelvic area decreased from 3mPP to 6mPP. During the straining maneuver, B-PCL, bladder neck descent, levator hiatus area, and LPA showed statistically significant differences (P < 0.05). In the resting state, the OIM area and PRT decreased whereas the anterior pelvic area increased from BP to 6mPP. During the straining maneuver, B-PCL, muscular pelvic floor relaxation line, and bladder neck descent showed statistically significant differences (P < 0.05).
Vaginal delivery can cause pelvic floor injury that may gradually recover over time. However, the injury does not fully recover to the pre-pregnancy level within 6mPP.
经阴道分娩是盆底功能障碍的主要危险因素之一。磁共振成像（MRI）有助于在静态和动态环境下对盆底的形态和功能进行定量评估。本研究的目的是调查初产妇在怀孕前（BP）和阴道分娩后盆底形态和功能的变化。
初产妇在怀孕前、产后3个月（3mPP）和产后6个月（6mPP）接受盆底MRI扫描。测量了各种盆底MRI数据，包括闭孔内肌（OIM）面积、骨盆前部面积、耻骨直肠肌厚度（PRT）、提肌板角度（LPA）、髂尾肌角度、膀胱-耻骨尾骨线（B-PCL）、子宫-耻骨尾骨线（U-PCL）、耻骨直肠裂孔线、肌肉盆底松弛线、提肌裂孔面积、尿道活动度、膀胱颈下降和宫颈下降。
在静息状态下，从BP到3mPP，OIM面积和PRT减小，而骨盆前部面积增加。在用力动作期间，除U-PCL和尿道活动度外，所有参数均显示出统计学显著差异（P < 0.05）。从3mPP到6mPP，OIM面积和PRT增加，而骨盆前部面积减小。在用力动作期间，B-PCL、膀胱颈下降、提肌裂孔面积和LPA显示出统计学显著差异（P < 0.05）。在静息状态下，从BP到6mPP，OIM面积和PRT减小，而骨盆前部面积增加。在用力动作期间，B-PCL、肌肉盆底松弛线和膀胱颈下降显示出统计学显著差异（P < 0.05）。
阴道分娩可导致盆底损伤，损伤可能会随着时间逐渐恢复。然而，在产后6个月内，损伤并未完全恢复到怀孕前水平。
