The Friedman Curve of Normal Labor, based on Emanuel Friedman's studies of Caucasian women in 1954 and 1955, remains the “gold standard” for assessing progress in the second stage of labor. Clinical observation by the authors, however, suggests that the second stage of labor is shorter in African American and Puerto Rican women.
This descriptive, comparative study examined the duration of the second stage of labor in nulliparous African American and Puerto Rican women with uncomplicated births. The labor and delivery records of 373 African American and 157 Puerto Rican nulliparous women were randomly selected and reviewed, and the mean durations of the second stage of labor for both groups were compared to Friedman's labor curve.
The mean length of second stage of labor in the sample of African American women was 31.6 minutes with a standard deviation of +22.5 minutes, significantly shorter than Friedman's duration (P < .01). The mean length of second stage of labor in the sample of Puerto Rican women was 44.32 minutes with a standard deviation of +33.03 minutes. This was also shorter than Friedman's figure for the second stage of labor (P < .01). These findings provide a more appropriate curve for monitoring labor progress in women from different ethnic backgrounds.