Multiple courses of betamethasone to enhance fetal lung maturation do not suppress neonatal adrenal response

OBJECTIVE: Our purpose was to evaluate the neonatal adrenal gland by provoc ative testing in neonates of mothers who had received multiple courses of b etamethasone to enhance fetal lung maturity. STUDY DESIGN: Infants of mothers who had received greater than or equal to 3 courses of betamethasone for fetal lung maturation were enrolled in the s tudy. Twenty-four hours after delivery a baseline serum cortisol concentrat ion was obtained. A synthetic adrenocorticotropic hormone (Cortrosyn) was a dministered (0.25 mg/1.73 m(2)). Two hours later a second serum cortisol co ncentration was obtained. An increase in serum cortisol in response to Cort rosyn was considered a positive test result. Nominal data were compared by means of the Student t-test. RESULTS: There were 9 infants enrolled in the study. The mean number of bet amethasone treatment cycles was 4.8 +/- 1.09. The mean baseline cortisol le vel was 2.23 +/- 0.52 mu g/dL, and the mean post-adrenocorticotropic hormon e cortisol level was 9.86 +/- 1.70 mu g/dL. All neonates had a positive adr enocorticotropic hormone test result. Stepwise linear regression showed no association between the number of courses of betamethasone treatment cycles and the post-adrenocorticotropic hormone cortisol concentration. CONCLUSION: Multiple weekly treatment cycles of betamethasone for fetal lun g maturity administered between 24 and 34 weeks' gestation do not appear to cause adrenal suppression.