Adrenocortical reserve of neonates born of long-term, steroid-treated mothers.

Since corticosteroids have been shown to be transferred across the human placenta, prolonged administration of these drugs during gestation could be expected to suppress the response of the neonatal adrenal gland. Plasma cortisol levels, before and 30 min after the injection of ACTH (36 micrograms/kg), were determined in six neonates who were exposed in utero to prolonged maternal administration of prednisone. The basal plasma cortisol levels of these neonates (6.15 +/- 2.57 micrograms %; mean +/- SEM) were similar to values obtained in eight healthy neonates (5.19 +/- 1.36 micrograms %). The increment of cortisol levels after ACTH stimulation (16.4 +/- 2.07 micrograms %) of the study patients was larger (P less than 0.01) than the change (10.3 +/- 0.82 micrograms %) observed in six older controls. These results indicate a normal neonatal adrenal reserve after prolonged exposure to corticosteroids during fetal life.