Liu Tianhang, Feng Fuqing, Shen Liang, Sun Hao, Tian Yongjie, Wang Xietong, Li Aihua, Hou Xiaoman
Department of Obstetrics and Gynecology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China.
Department of Obstetrics and Gynecology, Liaocheng People's Hospital, Liaocheng, China.
Abdom Radiol (NY). 2025 May 26. doi: 10.1007/s00261-025-04989-7.
Dimensions of the bony birth canal are hypothesized to be associated with pelvic organ prolapse (POP). However, the pelvic midplane, which represents the narrowest obstetrical plane, has not been thoroughly investigated. This study aims to compare the bony dimensions at the level of the pelvic midplane in childbearing women with and without POP and to evaluate their association with POP.
Data from 131 patients with POP were prospectively collected between 2021 and 2023. A total of 85 cases were matched with 85 controls who had comparable demographic characteristics. A case-control study was conducted to compare bony dimensions at the pelvic midplane level between women with and without POP using 3D MRI models. Additionally, analysis of covariance was performed to examine the relationship between these dimensions and the maximum prolapse.
The comparison of dimensions (in centimeters) between 85 cases and 85 controls revealed the following significant differences: anterior-posterior diameter (11.3 ± 0.7 vs. 10.7 ± 0.7, p < 0.001); pubic symphysis to ischial spine-left (9.4 ± 0.4 vs. 9.1 ± 0.4, p < 0.001),-right (9.5 ± 0.4 vs. 9.1 ± 0.4, p < 0.001); Ischial spine to sacrococcygeal junction-left (6.7 ± 0.5 vs. 6.5 ± 0.5, p = 0.002),-right (6.7 ± 0.5 vs. 6.5 ± 0.5, p = 0.002); interspinous diameter (11.1 ± 0.7 vs. 10.8 ± 0.7, p = 0.004); and the area of the pelvic midplane (63.0 ± 0.6 vs. 58.5 ± 0.6 cm, p < 0.001). A larger pelvic midplane was significantly associated with an increased risk of prolapse, with an odds ratio of 2.534 (95% CI 1.647-3.901, p < 0.001) for every 5 cm increase. Classification based on the presence or absence of prolapse showed that receiver operating characteristic analysis yielded an area under curve of 70.3% (p < 0.001). Furthermore, among POP patients, those with a larger pelvic midplane area exhibited more severe prolapse (trend p = 0.017).
Women with POP have significantly larger bony dimensions at the level of the pelvic midplane compared to women without POP. Additionally, advanced prolapse is associated with larger mid-pelvic dimensions.
推测骨性产道的尺寸与盆腔器官脱垂（POP）有关。然而，代表最窄产科平面的骨盆中平面尚未得到充分研究。本研究旨在比较有和没有POP的育龄妇女骨盆中平面水平的骨性尺寸，并评估它们与POP的关联。
前瞻性收集了2021年至2023年间131例POP患者的数据。总共85例病例与85例具有可比人口统计学特征的对照进行匹配。进行了一项病例对照研究，使用3D MRI模型比较有和没有POP的女性在骨盆中平面水平的骨性尺寸。此外，进行了协方差分析以检查这些尺寸与最大脱垂之间的关系。
85例病例和85例对照之间的尺寸（以厘米为单位）比较显示出以下显著差异：前后径（11.3±0.7对10.7±0.7，p<0.001）；耻骨联合至坐骨棘-左侧（9.4±0.4对9.1±0.4，p<0.001），-右侧（9.5±0.4对9.1±0.4，p<0.001）；坐骨棘至骶尾关节-左侧（6.7±0.5对6.5±0.5，p=0.002），-右侧（6.7±0.5对6.5±0.5，p=0.002）；棘间径（11.1±0.7对10.8±0.7，p=0.004）；以及骨盆中平面面积（63.0±0.6对58.5±0.6平方厘米，p<0.001）。骨盆中平面越大，脱垂风险显著增加，每增加5厘米，优势比为2.534（95%CI 1.647-3.901，p<0.001）。基于脱垂的存在与否进行分类显示，受试者操作特征分析得出曲线下面积为70.3%（p<0.001）。此外，在POP患者中，骨盆中平面面积较大的患者脱垂更严重（趋势p=0.017）。
与没有POP的女性相比，患有POP的女性在骨盆中平面水平的骨性尺寸显著更大。此外，严重脱垂与更大的中骨盆尺寸有关。
