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Evaluation of the labor curve in nulliparous Japanese women
Ritsuko Suzuki1, Shigeko Horiuchi, Hiroshi Ohtsu
1Department of Nursing, Kyorin University Hospital, Tokyo, Japan.
Objective:
We sought to compare Japanese nulliparous labor progression with Friedman's classic 1955 curve and Zhang's 2002 curve.
Study Design:
We developed a labor curve using retrospective record reviews of 2369 Japanese nulliparas, at term, spontaneous labor onset and singleton vertex deliveries of normal birth weight infants.
Results:
The new Japanese Suzuki-Horiuchi labor curve with slower cervical dilation in the active phase was like Zhang's and differed from Friedman's curve. Labor length was approximately 5 hours occurring between 4-10 cm compared with Friedman's 2.5 hours and Zhang's 5.5 hours. Even at 10-cm dilation, labor lasted >2 hours at the 95th percentile of time interval.
Conclusion:
Similar to Zhang's curve, the Suzuki-Horiuchi curve was smooth and more gradually sloped than Friedman's curve. Appraise "arrested or protracted labor" with these slower labor curves in mind using Friedman's curve cautiously.
