Fetal and neonatal glucose and lactate levels and acid-base balance after continuous maternal infusion of 5% dextrose at 180 mL/h (9 g/h) was compared with 0.9% saline solution in a prospective, randomized study from selected monitored labors. An infusion of 5% dextrose produced significantly increased glucose levels in maternal (p < 0.01), cord artery (p < 0.01), and cord vein (p < 0.001) blood. An increased maternal insulin level was also present (p < 0.05), but no differences in cord insulin levels were observed. beta-Hydroxybutyrate was lower in maternal (p < 0.05) and cord vein (p < 0.01), but not in cord artery blood, after maternal dextrose infusion. No significant changes occurred in blood lactate levels between the two groups in either mother, fetus, cord, or neonate. Acid-base balance in cord blood did not differ between the two groups. Maternal infusion of 5% dextrose at 180 mL/h (9 g/h), compared with saline solution, produces higher glucose levels in both mother and fetus, but increased insulin concentrations only in the mother. Dextrose infusion also lowers beta-hydroxybutyrate in maternal and cord vein blood. No differences were seen in lactate levels or cord acid-base balance. Both regimens seem safe according to risks for lactacidosis and neonatal hypoglycemia in the normoxemic, normal size fetus.