Spontaneous labor curve based on a retrospective multi-center study in Japan

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K18225
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 56040:Obstetrics and gynecology-related
• Research Institution: Yokohama City University
• Principal Investigator: Shindo Ryosuke 横浜市立大学, 附属市民総合医療センター, 助教 (20867858)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 分娩第一期活動期 / 分娩曲線 / 分娩第一期潜伏期 / 分娩進行 / フリードマン曲線 / 産科

Outline of Final Research Achievements

In Japan, the Friedman curve has generally been used as a criterion for evaluating the progress of labor in obstetric facilities. However, it has been pointed out that recent delivery progression differs from the Friedman curve. The American College of Obstetricians and Gynecologists/American Society of Maternal Fetal Medicine defines the active phase as the cervix opening after 6 cm, and the World Health Organization defines it after 5 cm, but there is no clear definition in Japan. The purpose of this study was to investigate the beginning of the active phase of the first stage of labor by expressing the smooth course of labor as a "spontaneous labor curve" using data from Japan. The delivery curves, which were created using delivery data from three university hospitals and one secondary care facility in Japan, indicate that the active phase of the first stage of labor begins after the opening of the uterus at 5 cm.

Free Research Field

産科学

Academic Significance and Societal Importance of the Research Achievements

分娩第一期の活動期の開始を定義することは産科医療の臨床上非常に重要な課題であった。分娩第一期の進行が順調でない場合、潜伏期であれば基本的には介入は不要であるが、一方で活動期以降は陣痛促進などの介入が考慮されるからである。本研究により分娩第一期の活動期の開始が定義されたことで、まだ潜伏期にあり、介入が不要な例に対する不適切な陣痛促進などが減少し、我が国の産科医療の安全性の向上が期待される。さらに、本研究成果が日本産科婦人科学会の診療ガイドライン産科編2023に引用されたことから、今後我が国の産科医療の現場で広まっていくことが期待される。