The Natural History of the Normal First Stage of Labor
The Natural History of the Normal First Stage of Labor
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DOI：
10.1097/aog.0b013e3181d55925
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发表时间：
2010-04-01
影响因子：
7.2
通讯作者：
Fraser, William
中科院分区：
文献类型：
--
作者：
Zhang, Jun;Troendle, James;Fraser, William
目的：检查大量人群的临产模式，并探索诊断异常临产进展的替代方法。方法：使用来自国家围产期合作项目的数据。总共选择了 26,838 名单胎足月妊娠、自然临产、头顶先露和围产期结局正常的产妇。使用重复测量分析来构建按胎次划分的平均劳动力曲线。使用间隔删失回归来估计按入院时宫颈扩张和逐厘米分层的产程持续时间。 结果：随着产程的推进，从一厘米进展到下一厘米所需的中位时间变得更短（例如，未产妇从 3-4 厘米时的 1.2 小时缩短到 7-8 厘米时的 0.4 小时）。未生育过的女性的产程曲线最长、最平缓。不同胎次的多产妇女的曲线非常相似。 Nulliparas可能会在宫颈扩张5厘米后开始活跃期，但不一定有一个以急剧扩张为特征的明确活跃期。在许多情况下，产程活跃期后期的减速期可能是人为因素。结论：经产妇的产程活跃期可能要到宫颈扩张5 cm才开始，而未产妇的宫颈扩张则更晚。在扩张 6 厘米之前，诊断分娩停止的 2 小时阈值可能太短，而在扩张 6 厘米之后，4 小时的限制可能太长。鉴于宫颈扩张随着产程进展而加速，因此提出了一种基于宫颈扩张水平的分级方法来诊断产程延长和停产。 （妇产科 2010 年；115：705-10）
OBJECTIVE: To examine labor patterns in a large population and to explore an alternative approach for diagnosing abnormal labor progression.METHODS: Data from the National Collaborative Perinatal Project were used. A total of 26,838 parturients were selected who had a singleton term gestation, spontaneous onset of labor, vertex presentation, and a normal perinatal outcome. A repeated-measures analysis was used to construct average labor curves by parity. An interval-censored regression was used to estimate duration of labor stratified by cervical dilation at admission and centimeter by centimeter.RESULTS: The median time needed to progress from one centimeter to the next became shorter as labor advanced (eg, from 1.2 hours at 3-4 cm to 0.4 hours at 7-8 cm in nulliparas). Nulliparous women had the longest and most gradual labor curve; multiparous women of different parities had very similar curves. Nulliparas may start the active phase after 5 cm of cervical dilation and may not necessarily have a clear active phase characterized by precipitous dilation. The deceleration phase in the late active phase of labor may be an artifact in many cases.CONCLUSION: The active phase of labor may not start until 5 cm of cervical dilation in multiparas and even later in nulliparas. A 2-hour threshold for diagnosing labor arrest may be too short before 6 cm of dilation, whereas a 4-hour limit may be too long after 6 cm. Given that cervical dilation accelerates as labor advances, a graduated approach based on levels of cervical dilation to diagnose labor protraction and arrest is proposed. (Obstet Gynecol 2010; 115: 705-10)