Re-evaluation of the definition of prolonged labor

2010 Fiscal Year Final Research Report

• Project/Area Number: 20592586
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Lifelong developmental nursing
• Research Institution: Oita University
• Principal Investigator: ANAI Takanobu Oita University, 医学部, 教授 (00202648)
• Co-Investigator(Kenkyū-buntansha): MIYAZAKI Fumiko 大分大学, 医学部, 准教授 (10315195)
• Project Period (FY): 2008 – 2010
• Keywords: 遷延分娩 / 初産婦 / 経産婦 / 新生児体重 / 妊婦体重増加量

Research Abstract

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.