Chronic oral terbutaline tocolytic therapy is associated with maternal glucose intolerance

Plasma glucose determinations were performed 1 hour after a 50 gm oral glucose load in 30 patients receiving long-term terbutaline therapy (20 to 40 mg/day for at least 1 week) and 247 normal control patients. A total of 63% of patients receiving terbutaline had an abnormal 1-hour value (greater than or equal to 140 mg/dl), an incidence much higher than that of control subjects (17.8%) (p less than 0.0001) for a relative risk of 3.54 (95% confidence intervals of 2.29 to 5.42). Mean 1-hour values were 112.1 mg/dl for control subjects and 149.8 mg/dl in the terbutaline group (p less than 0.0001). All abnormal values were followed by a 3-hour 100 gm oral glucose tolerance test. A total of 15.9% of the glucose tolerance tests performed in the control group (2.8% overall) were abnormal as opposed to 52.6% (33.1% overall) in patients receiving terbutaline (p less than 0.01). Nine patients were studied before and after terbutaline therapy. Results obtained during administration of terbutaline were significantly higher (102.2 mg/dl before therapy versus 145.2 mg/dl during therapy). We conclude that treatment with oral terbutaline appears to be associated with impairment of glucose tolerance in pregnancy.