PCEA started at the beginning of the first labor process. The period of labor,VAS,labor mode and Apgar score were recorded at each labor process.

• PCEA组在第一产程活跃期开始施行PCEA ,记录两组产妇分娩过程中的产程时间、产程各时段的视觉模拟评分 (VAS)、分娩方式及新生儿Apgar评分。