Carbohydrate intolerance in patients receiving oral tocolytics

Abstract

This prospective study was designed to evaluate the effects on glucose metabolism of terbutaline used as an oral tocolytic agent. Eighty-six patients were studied when admitted for preterm labor from 24 to 35 weeks' gestation. After intravenous tocolysis, these patients were maintained on 5 mg of terbutaline every 4 or 6 hours. An oral 50 gm, 1-hour glucose challenge test was done 48 hours after terbutaline dosing began. All abnormal glucose challenge test results (greater than or equal to 135 mg/dl) were followed by a standard 100 gm oral glucose tolerance test. Sixty-three percent (54 of 86) of the terbutaline group had an abnormal 1-hour screening result, which was significantly different than the 26.7% (23 of 86) observed in the control group (p less than 0.001). The mean fasting blood sugar and 1-hour postchallenge values were significantly higher in the study than in the control group (p less than 0.0001). Ten of 86 in the treated group (11.6%) and 2 of 86 in the control group (2.3%) with abnormal results met the criteria for gestational diabetes. These numbers achieve statistical significance at p less than 0.05. This study shows a significant effect of oral terbutaline therapy on glucose tolerance during pregnancy. Patients receiving oral terbutaline therapy for suppression of preterm labor should undergo screening for gestational diabetes.