Department of Obstetrics and Gynecology, Østfold Hospital Trust, PO.box 300, 1714, Grålum, Norway.
Department of Health, Nutrition and Management, Faculty of Health Sciences, Oslo and Akershus University College of Applied Sciences, Oslo, Norway.
BMC Pregnancy Childbirth. 2017 Nov 13;17(1):370. doi: 10.1186/s12884-017-1553-8.
The increasing rate of intrapartum cesarean sections is subject of attention and concern as it is associated with adverse outcomes. Labor dystocia is one of the most frequent indications for cesarean sections even though there is no consensus on criteria for labor dystocia. Traditionally the progression of labor follows guidelines based on Friedman's curve from the mid 1950s. In 2010 Zhang presented a new labor curve and a dynamic guideline for labor progression based on contemporary research. The main aim of this trial is to evaluate whether adhering to Zhang's guideline for labor progression, changes the intrapartum cesarean section rate in nulliparous women without jeopardising maternal and neonatal outcomes compared to a traditional guide line called the 4-h action line based on Friedman's curve.
METHODS/DESIGN: A multicenter cluster randomized trial including 14 birth care units in Norway is conducted. Seven units are randomized to use the 4-h action line guideline for labor progression and seven units are randomized to use Zhang's new dynamic guideline for labor progression, for all nulliparous women with a singleton fetus in a cephalic presentation and spontaneous onset of labor at term. Clinical outcomes are compared between the groups. The determination of the sample size (number of clusters and individuals) is based on a power calculation of intrapartum cesarean section, which is 9.2% in the study population (p1). Further, we expect that the intrapartum cesarean section rate will be 6.7% (p2) which is a 25% reduction, when using the new guideline. With a chosen significance level of 0.05, a power of 80% and p1 = 9.2% and p2 = 6.9%, we should include at least 14 clusters and 6582 individuals.
Clinical consequences when using the guideline by Zhang have, to the best of our knowledge, not been investigated earlier. The results will provide a strong basis to make a qualified decision on whether it is beneficial to introduce a dynamic labor progression curve in contemporary obstetrics both nationally and internationally.
Clinicaltrials, NCT02221427.
由于与不良结局相关，产程中剖宫产率的不断上升引起了人们的关注和担忧。尽管对于产程延长的标准尚无共识，但分娩困难仍是剖宫产最常见的指征之一。传统上，产程的进展遵循基于弗里德曼曲线的指南，该指南源自 20 世纪 50 年代中期。2010 年，张提出了一种新的产程曲线和基于当代研究的产程进展动态指南。本试验的主要目的是评估在不影响母婴结局的情况下，与基于弗里德曼曲线的 4 小时行动线传统指南相比，遵循张的产程进展指南是否会改变初产妇的产程中剖宫产率。
方法/设计：本研究是一项多中心、集群随机试验，包括挪威的 14 个分娩护理单位。7 个单位被随机分配使用 4 小时行动线产程进展指南，7 个单位被随机分配使用张的新的产程进展动态指南，用于所有初产妇、单胎、头位、足月、自发临产。对两组的临床结局进行比较。样本量（集群和个体数量）的确定是基于产程中剖宫产的功效计算，在研究人群中为 9.2%（p1）。此外，我们预计当使用新指南时，产程中剖宫产率将降低 25%，为 6.7%（p2）。选择显著性水平为 0.05，功效为 80%，p1=9.2%，p2=6.9%，我们应该包括至少 14 个集群和 6582 名个体。
就我们所知，使用张的指南的临床后果尚未被更早地研究过。该结果将为是否在全国和国际范围内引入现代产科动态产程曲线提供有力依据，以便做出有资质的决策。
Clinicaltrials.gov，NCT02221427。
