Effect of betamethasone on maternal glucose

To determine the effect of single and multiple betamethasone courses on maternal fasting and postprandial glucose values.

A prospective cohort study was performed in women receiving betamethasone at 24-34 weeks' gestation. Fasting and 1-h postprandial capillary glucose values were obtained daily following betamethasone therapy for hospitalized patients. A control group comprised outpatients who underwent weekly fasting and postprandial assessments for 3 weeks. Fasting and 1-h postprandial capillary glucose values were compared between control and betamethasone patients using an unpaired t test.

Thirty-five women received a single course of therapy, 19 received multiple courses and 28 served as controls. Mean fasting glucose values for control patients fell within a narrow range of 81.6 +/- 10.3 to 82.2 +/- 6.4 mg/dl for weeks 1-3. Of women receiving betamethasone, 59% of fasting glucose values were greater than 90 mg/dl as compared to 16% of control fasting values (p < 0.00 1, chi2 test). Mean 1-h postprandial values for control women ranged from 107.7 +/- 15.1 to 112.3 +/- 20.0 mg/dl for weeks 1-3. Mean 1-h postprandial glucose values were < or = 140 mg/dl following one, two or three courses of betamethasone therapy.

Betamethasone resulted in an acute increase in fasting glucose following a single course of betamethasone, whereas two or more courses of therapy resulted in a continuous elevation of fasting glucose values. One-hour postprandial values were not clinically abnormal.