Because maternal hyperglycemia during labor foretells neonatal hypoglycemia and subsequent neurodevelopmental impairment, aggressive control of intrapartum maternal plasma glucose levels has been proposed. Current guidelines recommend continuous low-dose insulin infusion for women with insulin-dependent diabetes. The present investigators have alternated glucose-containing IV fluids with fluids lacking glucose, based on measurements of capillary blood glucose (CBG).
This randomized trial compared glycemic control using these two techniques in 36 women in labor who had pregestational or gestational insulin-requiring diabetes. Fifteen women received “rotating” fluids, whereas 21 had an insulin drip. The participants, all of whom were past 20 weeks’ gestational age, presented during spontaneous labor or for induction. The women monitored their fasting and 1-hour postprandial CBG levels using a home glucometer. In the insulin drip group, women received 5% dextrose in normal saline and insulin was added when the maternal CBG exceeded 80 mg/dL. Women in the rotating fluids group received 5% dextrose in normal saline when the CBG was 100 mg/dL or lower, and lactated Ringers solution if the CBG was in the range 101–140 mg/dL; an insulin drip was started if the CBG exceeded 140 mg/dL.
Patients randomized to the two management groups were similar in maternal age, median gestational age, nulliparity, gestational versus pregestational diabetes, and daily insulin requirements. There were no differences in the rates of induced versus spontaneous labor, vaginal versus cesarean delivery, or the median duration of labor. Mean intrapartum maternal CBG levels were comparable in patients managed by the rotating fluids and insulin drip protocols (103.9 and 103.2 mg/dL, respectively). None of the mothers became hypoglycemic. Neonatal outcomes were similar in the two groups. Two newborn infants in the insulin drip group required IV dextrose for persistent neonatal hypoglycemia which was defined as a blood sugar less than 35 mg/dL in the first 24 hours of life. By this definition, neonatal hypoglycemia was recorded in 7% of the rotating fluids group and 19% of the insulin drip group—not a significant difference.
The investigators suggest that an insulin drip need not be routinely used in well-controlled women with either pregestational or gestational insulin-dependent diabetes. Rotating between IV fluids with and without glucose may achieve comparable control.
Department of Obstetrics and Gynecology, Weill Medical College of Cornell University, New York, New York; and Department of Obstetrics and Gynecology, New York Hospital Medical Center of Queens, Flushing, New York
Am J Obstet Gynecol 2006;195:1095–1099