Division of Maternal-Fetal Medicine and Obstetrics, Stanford University, Stanford, CA 94305, USA.
Semin Perinatol. 2012 Oct;36(5):374-8. doi: 10.1053/j.semperi.2012.04.022.
To assess the thresholds of normal and protracted labor in contemporary US parturients. Select studies addressing first- and second-stage labor duration among contemporary cohorts of women in the United States were reviewed. Particular emphasis was placed on the work of the Consortium on Safe Labor. Duration of labor appears longer today than in the past. For both nulliparous and multiparous women, labor may take >6 hours to progress from 4 to 5 cm and >3 hours to progress from 5 to 6 cm of dilation. A cervical dilation of 6 cm appears to be a better landmark for the start of the active phase. The 95th percentile for duration of the second stage in a nulliparous woman with conduction anesthesia is closer to 4 hours. Current data on first and second stages of labor allow for an opportunity to reconsider traditionally accepted thresholds of normal and protracted labor, and thus affect consequent labor management paradigms.
评估当代美国产妇正常和延长产程的界限。对在美国当代队列女性的第一产程和第二产程持续时间的相关研究进行了回顾。特别强调了安全分娩联合会的工作。与过去相比，如今的产程似乎更长。对于初产妇和经产妇，从宫口扩张 4cm 进展至 5cm 可能需要超过 6 小时，从宫口扩张 5cm 进展至 6cm 可能需要超过 3 小时。宫口扩张 6cm 似乎是活跃期开始的更好标志。有硬膜外麻醉的初产妇第二产程的 95 百分位数更接近 4 小时。目前关于第一产程和第二产程的数据为重新考虑传统上接受的正常和延长产程的界限提供了机会，从而影响后续的分娩管理模式。
