Objective: To determine if one course of antenatal corticosteroids at 32 weeks produces maternal adrenal suppression at term.
Methods: The adrenocorticotropic hormone (ACTH) stimulation test was administered at 38 weeks to 11 pregnant women who had received a single course of antenatal betamethasone prior to 33 weeks and to six control subjects.
Results: There was no difference in basal cortisol levels (mean+/-standard deviation) between the two groups: 41.6+/-6.9 microg/dl for controls versus 36.0+/-7.8 microg/dl for the steroid group, p=0.16. Peak cortisol levels at 45 min following ACTH stimulation were not different: 61.6+/-3.5 microg/dl for controls versus 55.0+/-2.6 microg/dl for the steroid group, p=0.16. The power of the study to detect a statistical difference in the observed peak cortisol levels was greater than 95%. None of the study subjects had laboratory criteria or clinical signs of adrenal suppression.
Conclusions: A single course of betamethasone for women at risk for preterm delivery does not produce adrenal insufficiency at term and stress dose steroids are not recommended.