Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway.
Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway.
Int Urogynecol J. 2022 Dec;33(12):3529-3534. doi: 10.1007/s00192-022-05111-x. Epub 2022 Mar 1.
Slow progress of labour is a risk for operative delivery. Smaller levator hiatal dimensions are possible risk factors for slow progress and operative delivery. Our aim was to explore associations between hiatal dimensions antenatally, duration of second stage of labour and mode of delivery.
Prospective cohort study of 65 nullipara examined at 20 weeks gestation and 6 months postpartum. Levator hiatal anteroposterior diameter and area were measured using 2D/3D transperineal ultrasound and compared between women with normal vaginal delivery and operative delivery (vacuum or caesarean) using t-test and with Spearman's rank to explore correlations with duration of second stage. ROC analysis established a cut-off for high risk of operative delivery.
Two-dimensional anteroposterior diameter and 3D hiatal area at rest were smaller in women with operative delivery than with normal delivery, 5.0 cm vs. 5.7 cm, p = 0.007 and 18.5 cm vs. 14.9 cm, p < 0.001. From the ROC curve for 2D anteroposterior diameter, a cut-off of 5.6 cm, (sensitivity = 0.94, specificity = 0.63) and for 3D hiatal area a cut-off of 17.6 cm (sensitivity = 0.94, specificity = 0.65) predicted operative delivery. We found inverse correlations between second stage of labour and anteroposterior diameter at rest, r = -0.330, contraction, r = -0.365, area at rest, r = -0.324, and contraction, r = -0.521, all p < 0.05.
Smaller hiatal dimensions at 20 weeks gestation were associated with longer second stage of labour and increased risk of operative delivery in nullipara. A 2D anteroposterior hiatal diameter < 5.6 cm and 3D hiatal area < 17.6 cm at rest imply increased risk of operative delivery.
分娩进展缓慢是行剖宫产术的一个风险因素。较小的肛提肌裂孔尺寸可能是分娩进展缓慢和需要行剖宫产术的潜在风险因素。我们的目的是探讨产前裂孔尺寸与第二产程持续时间和分娩方式之间的关系。
对 65 例初产妇进行前瞻性队列研究，分别在 20 周妊娠和产后 6 个月进行检查。使用二维/三维经会阴超声测量肛提肌裂孔前后径和面积，并采用 t 检验比较正常阴道分娩和手术分娩（真空吸引或剖宫产）妇女之间的差异，采用 Spearman 秩相关分析探讨与第二产程持续时间的相关性。ROC 分析确定手术分娩的高危截点。
手术分娩组妇女的二维前后径和 3D 裂孔面积在休息时均小于正常分娩组，分别为 5.0cm 比 5.7cm，p=0.007 和 18.5cm 比 14.9cm，p<0.001。二维前后径 ROC 曲线的截点为 5.6cm（敏感性=0.94，特异性=0.63），3D 裂孔面积的截点为 17.6cm（敏感性=0.94，特异性=0.65），可预测手术分娩。我们发现第二产程与休息时的前后径呈负相关，r=-0.330，收缩时为 r=-0.365，休息时的面积呈负相关，r=-0.324，收缩时为 r=-0.521，所有 p 值均<0.05。
20 周妊娠时较小的裂孔尺寸与较长的第二产程和初产妇行剖宫产术的风险增加相关。休息时二维前后径裂孔直径<5.6cm 和 3D 裂孔面积<17.6cm 提示手术分娩的风险增加。
