Objective: The objective of the study was to compare intravenous normal saline with and without dextrose on the course of labor in nulliparae. Study Design: In a double-blinded, controlled trial, term, nulliparae with singletons in active labor were randomized into 1 of 3 groups receiving either normal saline (NS), NS with 5% dextrose (D5NS), or NS with 10% dextrose (D10NS) at 125 mL/h. The primary outcome was total length of labor from onset of study fluid in vaginally delivered subjects. Maternal and neonatal outcomes were also analyzed. Results: Of 300 subjects enrolled, 289 met inclusion criteria and completed the study. In vaginally delivered subjects, significant differences were noted in the second stage (P = .01) and total length of labor (P = .02). No significant differences were observed in the cesarean section rates between the groups (P = .21). No differences were noted in maternal or neonatal secondary outcomes. Conclusion: Administration of a dextrose solution, regardless of concentration, was associated with a shortened labor course in term vaginally delivered nulliparae subjects in active labor. © 2009 Mosby, Inc. All rights reserved.