Department of Obstetrics and Gynecology, Sant'Orsola Malpighi University Hospital, University of Bologna, Bologna, Italy.
Department of Obstetrics and Gynecology, Kasr Al-Ainy University Hospital, Cairo University, Egypt.
Ultrasound Obstet Gynecol. 2019 May;53(5):686-692. doi: 10.1002/uog.20159. Epub 2019 Apr 2.
To assess the effect of levator ani muscle (LAM) coactivation at term on outcome of labor in nulliparous women.
This was a prospective study of 284 low-risk nulliparous women with a singleton pregnancy at term recruited before the onset of labor. The anteroposterior diameter of the levator hiatus was measured in each woman on transperineal ultrasound at rest, on maximum pelvic floor muscle contraction and on maximum Valsalva maneuver before and after visual feedback. LAM coactivation was defined as a reduction in the anteroposterior diameter of the levator hiatus on maximum Valsalva maneuver in comparison with that at rest. The association of pelvic hiatal diameter values and LAM coactivation with mode of delivery and duration of labor was assessed.
No significant difference was found between women who underwent Cesarean delivery and those who had a vaginal delivery with regard to the anteroposterior diameter of the levator hiatus at rest, on pelvic floor muscle contraction and on Valsalva maneuver. Longer second stage of labor was associated with shorter anteroposterior diameter of the levator hiatus on all assessments, but in particular at rest and on Valsalva both before and after visual feedback. LAM coactivation was found in 89 (31.3%) and 75 (26.4%) women before and after visual feedback, respectively. Post visual feedback, women with LAM coactivation had a significantly longer second stage of labor than did those without LAM coactivation (83 ± 63 vs 63 ± 42 min; P = 0.006). On Cox regression analysis, LAM coactivation post visual feedback was an independent predictor of longer second stage of labor (adjusted hazard ratio, 1.499 (95% CI, 1.076-2.087); P = 0.017).
LAM coactivation in nulliparous women at term is associated with a longer second stage of labor. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.
评估足月时肛提肌（LAM）协同收缩对初产妇分娩结局的影响。
这是一项前瞻性研究，共纳入 284 例足月、单胎、低危初产妇。在分娩开始前，采用经会阴超声测量每位产妇静息、最大盆底肌收缩和最大 Valsalva 动作时肛提肌裂孔的前后径，并在视觉反馈前后测量 LAM 协同收缩时的肛提肌裂孔前后径。LAM 协同收缩定义为最大 Valsalva 动作时肛提肌裂孔前后径与静息时相比的减少。评估骨盆裂孔直径值和 LAM 协同收缩与分娩方式和产程时间的关系。
在静息、盆底肌收缩和 Valsalva 动作时，行剖宫产术的产妇与行阴道分娩的产妇之间，肛提肌裂孔的前后径无显著差异。第二产程较长与所有评估时的肛提肌裂孔前后径较短相关，尤其是在视觉反馈前后的静息和 Valsalva 时。89（31.3%）例和 75（26.4%）例产妇分别在视觉反馈前后出现 LAM 协同收缩。视觉反馈后，有 LAM 协同收缩的产妇第二产程明显长于无 LAM 协同收缩的产妇（83±63 比 63±42 分钟；P=0.006）。在 Cox 回归分析中，视觉反馈后 LAM 协同收缩是第二产程延长的独立预测因素（调整后的危险比，1.499（95%CI，1.076-2.087）；P=0.017）。
足月初产妇的 LAM 协同收缩与第二产程延长有关。版权所有 © 2018 ISUOG。由 John Wiley & Sons Ltd 出版。
