Effect of hydration on spontaneous labor outcomes in nulliparous pregnant women: a multicenter randomized controlled trial comparing three methods.

OBJECTIVE: To evaluate the effect of mode and amount of fluid hydration during labor.

STUDY DESIGN: The authors conducted a randomized controlled trial of uncomplicated nulliparous women in spontaneous labor at 36 weeks or more gestational age. Women were randomized to receive lactated Ringer solution with 5% dextrose at (1) 125 mL/h intravenously with limited oral intake, (2) 250 mL/h intravenously with limited oral intake, or (3) 25 mL/h intravenously with ad libitum oral intake of clear liquids. Results were analyzed by intent-to-treat analysis.

RESULTS: A total of 311 out of 324 women were available for analysis. Groups 1 (n = 105), 2 (n = 105), and 3 (n = 101) above did not differ significantly for mean labor duration (11.6 ± 5.9, 11.4 ± 5.5, and 11.5 ± 5.9 hours, respectively; p = 0.998), proportion of women in labor > 12 hours (all groups 41%; p = 0.998), proportion receiving oxytocin augmentation (59, 60, and 57%, respectively; p = 0.923), or proportion delivered by cesarean (22, 17, and 17%, respectively; p = 0.309). Indications for cesarean were similar between groups. No cases of pulmonary edema, maternal aspiration, or perinatal mortality occurred.

CONCLUSION: Although apparently safe, neither increased intravenous hydration nor oral hydration during labor improves labor performance.