Abstract：
The active phase of labor begins at various degrees of dilatation when the rate of dilatation transitions from the relatively flat slope of the latent phase to a more rapid slope. No diagnostic manifestations demarcate its onset, other than accelerating dilatation. It ends with apparent slowing of dilatation, a deceleration phase, which is usually short in duration and frequently undetected. Several aberrant labor patterns can be detected during the active phase, including protracted dilatation, arrest of dilatation, prolonged deceleration phase and failure of descent. Underlying factors may include cephalopelvic disproportion, excessive neuraxial block, poor uterine contractility, fetal malpositions, malpresentations, uterine infection, maternal obesity, advanced maternal age and previous cesarean delivery. When an active-phase disorder is identified, cesarean delivery is justifiable if there is compelling clinical evidence of disproportion. A prolonged deceleration disorder is strongly associated with disproportion and second stage abnormalities. Shoulder dystocia may occur if vaginal delivery eventuates. This review discusses several issues raised by the introduction of new clinical practice guidelines for labor management.
摘要：
当扩张速率从潜在阶段的相对平坦的斜率过渡到更快的斜率时，分娩的活跃阶段开始于各种扩张程度。没有诊断表现来区分它的发作，除了加速扩张。它以扩张明显放缓结束，减速阶段，通常持续时间短，经常未被发现。在活动阶段可以检测到几种异常的劳动模式，包括旷日持久的扩张，逮捕扩张，减速阶段延长和下降失败。潜在因素可能包括头盆比例失调，过度的神经轴阻滞，子宫收缩力差，胎儿错位,口误,子宫感染,产妇肥胖，高龄产妇和既往剖宫产。当发现活跃期紊乱时，如果有令人信服的临床证据表明比例不相称，剖宫产是合理的。长时间的减速障碍与比例失调和第二阶段异常密切相关。如果阴道分娩可能发生肩难产。这篇综述讨论了引入新的劳动管理临床实践指南提出的几个问题。
