OBJECTIVE To test the hypothesis that women receiving intrapartum amnioinfusion have more rapid labors than do controls. METHODS Prospective clinical trials of amnioinfusion published in major American obstetric and gynecologic journals between 1985 and 1995, identified through a literature search using MEDLINE and manual index review, were examined. METHODS Eleven studies that presented data regarding the length of labor were identified. Each study was reviewed for the design, number of subjects enrolled, volume of amnioinfusate, birth weight, maternal parity, interval from amniorrhexis to delivery, and total length of labor. RESULTS Meta-analysis revealed no differences between amnioinfusion groups and controls with regard to length of labor or the interval between membrane rupture and delivery. CONCLUSIONS Amnioinfusion has no effect on the duration of labor.