Intrapartum maternal glucose infusion reduces umbilical cord acidemia.

OBJECTIVE: Our purpose was to compare the effects of intrapartum 5% glucose in the intravenous fluid on umbilical cord acid-base and glucose status after spontaneous vaginal delivery.

STUDY DESIGN: This was a prospective randomized clinical trial in which gravid women with low-risk pregnancies at term were randomized by computer to receive lactated Ringer's solution, either with 5% glucose or without, as the maintenance intravenous fluid during active labor. Antepartum and intrapartum factors that might influence fetal-neonatal glucose levels were recorded. Umbilical arterial cord blood was assessed for glucose level and acid-base status.

RESULTS: Of the 106 parturient patients who consented, 15 were excluded because of operative delivery (n = 8), preeclampsia (n = 2), shoulder dystocia (n = 1), intravenous fluid infusion duration of < 1 hour (n = 1), and cord blood data not available (n = 3). There were no statistical differences between the two groups regarding maternal age, parity, maternal weight at term, epidural placement, intravenous fluid duration, or gestational age. Infant birth weight, gender, Apgar scores, and incidence of meconium were not statistically different. Neonatal hypoglycemic episodes and intrapartum fetal heart rate tracing parameters were similar between groups. The difference between the umbilical artery pH values of those who were treated with lactated Ringer's solution with 5% glucose (n = 48) versus those treated with the solution without glucose (n = 43) approached significance, with a p value of 0.08 (mean +/- SD, 7.30 +/- 0.07 and 7.27 +/- 0.09, respectively). The PCO2 value of those treated with lactated Ringer's solution without glucose was higher (mean +/- SD, 50.6 +/- 12.9 mm Hg vs 44.8 +/- 9.9 mm Hg) (p = 0.02). Base excess (in milliequivalents per deciliter) and cord glucose (in milligrams per deciliter) levels, as well as the incidence of neonatal hypoglycemic episodes within the first 8 hours of life, were not statistically different. Despite failure of mean pH differences to achieve significance, the relative risk (0.22) for an umbilical arterial pH < or = 7.20 was significantly reduced (95% confidence interval 0.1 to 0.7) with lactated Ringer's solution containing 5% glucose. The relative risk (0.42) of having an umbilical artery cord blood PCO2 value > or = 55 mm Hg was also significantly lowered (95% confidence interval 0.19 to 0.93) when lactated Ringer's solution containing 5% glucose was used.

CONCLUSIONS: Intrapartum intravenous fluid consisting of lactated Ringer's solution containing 5% glucose reduces umbilical cord acidemia and hypercarbia but does not change cord levels of glucose or base excess. Lactated Ringer's solution containing 5% glucose may be a preferable solution than without glucose as an intravenous fluid during labor.