Normal and abnormal labor progress: I. A quantitative assessment and survey of the literature.

Quantitative labor data have been reported piecemeal in the literature; there is no previous unified report of the frequencies of each of the dysfunctional labor patterns (DLPs). In order to describe the labor process more clearly a labor diagnostic computer program was used to prospectively study an unselected series of 3,682 nearly consecutive labors from one institution. Cervicometric data for nulliparous and multiparous labor were very similar to the results of others. The absolute frequency with which each DLP was found to occur is compared with results in the literature. Protracted active phase dilatation was the most frequently occurring DLP and prolonged deceleration phase the least frequently occurring one. The relative frequencies of the DLPs, defined as the percentage of all DLPs that occurred, remained reasonably constant, regardless of parity or the absolute frequencies of the DLPs in a group of patients.