A prospective randomized trial of two solutions for intrapartum amnioinfusion: Effects on fetal electrolytes, osmolality, and acid-base status

Objective: Our purpose was to compare the effects of intrapartum amnioinfusion with normal saline solution versus lactated Ringerʹs solution plus physiologic glucose on neonatal electrolytes and acid-base balance. Study Design: Patients undergoing amnioinfusion for obstetric indications were randomized to receive normal saline solution or lactated Ringerʹs solution plus physiologic glucose at standardized amnioinfusion rates. Data were collected prospectively on maternal demographics, course of labor, and maternal and neonatal outcome. Arterial cord blood was obtained for analysis of electrolytes, glucose, osmolality, lactic acid, and blood gases. Control subjects with normal fetal heart rate patterns, and clear amniotic fluid not receiving amnioinfusion were studied concurrently. Results: Data were collected on 59 patients (21 normal saline solution, 18 lactated Ringerʹs solution plus physiologic glucose, and 20 controls). Maternal demographics, course of labor, and neonatal outcome were similar in all three groups. Cesarean sections were performed more often in the amnioinfusion groups (33.3% for normal saline solution, 38.9% for lactated Ringerʹs solution plus physiologic glucose) than in the control group (5.0%), p<0.05. Cord arterial electrolytes, glucose, osmolality, lactic acid, and blood gases were not altered by amnioinfusion with either solution. Conclusion: Intrapartum amnioinfusion with normal saline solution or lactated Ringerʹs solution plus physiologic glucose has no effect on neonatal electrolytes or acid-base balance.