The effect of prenatal betamethasone administration on postnatal ovine hypothalamic-pituitary-adrenal function

Prenatal exposure to glucocorticoids is associated with alterations in fetal growth and endocrine function. However, few studies have examined the effects of clinically relevant doses of glucocorticoids on postnatal hypothalamic-pituitary-adrenal (HPA) function. To determine the effects of maternal or fetal betamethasone administration (0.5 mg/kg maternal or estimated fetal weight) on postnatal HPA function at 6 months and 1 year postnatal age, pregnant ewes were randomized into the following treatment groups: no treatment (n = 6); maternal saline (n = 6); single maternal betamethasone (M 1) (n = 6); repeated maternal betamethasone (M4) (n = 6); fetal saline (n = 5); single fetal betamethasone (n = 6) and repeated fetal betamethasone (F4) (n = 6). Single injections were given at 104 days of gestation and repeated injections at 104, 111, 118 and 125 days. Lambs were born spontaneously and the ACTH and cortisol responses to i.v. corticotropin-releasing hormone (CRH) (0.5 mug/kg) plus arginine vasopressin (AVP) (0.1 mug/kg) were measured at 6 months and 1 year postnatally. At 6 months postnatal age, neither maternal nor fetal prenatal betamethasone administration altered significantly the ACTH and cortisol responses to CRH+AVP. However, in animals at 1 year postnatal age, a previous single injection of betamethasone to the mother (M1) resulted in significantly elevated basal and stimulated cortisol levels (P