Re-evaluation of the definition of prolonged labor

日本妇产科学会将产程延长定义为连续产程超过30小时，连续产程超过15小时。这种定义分别对应于本研究中660例产妇和641例产妇的产程持续时间的第98百分位数和第97百分位数。第90百分位数的产程持续时间为20小时，产妇为10小时。经Mann-Whitney U检验，产程> 20 h的剖宫产组和产程> 10 h的多产组5 min Apgar评分明显降低（P分别为0.013和0.035）。这些发现表明，产程延长可以定义为分娩时间超过20小时，多次分娩超过10小时。

Japan Society of Obstetrics and Gynecology defines prolonged labor as labor more than 30 hours in primiparas and 15 hours in multiparas. Such a definition corresponds to 98th percentile and 97th percentile in duration of labor in 660 primiparas and 641 multiparas in present study, respectively. The 90th percentile of durations of labor was 20 hours in primiparas and 10 hours in multiparas. Using a Mann-Whitney U test, significant decreases in 5 minute Apgar score were found in primiparas with labor more than 20 hours and in multiparas with labor more than 10hours (P=0.013, P=0.035, respectively). These findings suggest that prolonged labor may be defined as labor more than 20 hours in primiparas and 10 hours in multiparas.