Programming effects in sheep of prenatal growth restriction and glucocorticoid exposure

Our aim was to determine the postnatal effects of single and repeated gluco corticoid injections during late gestation. Repeated (104, , 111, 118, 125 days) or single (104 days) injections of betamethasone or saline were given to the ewe or by ultrasound guided injection to the fetus (term 150 days). Lambs were born spontaneously and studied at 3 and 6 mo and 1 yr of age. A rterial pressure was measured at each age, and we performed intravenous glu cose tolerance tests at 6 mo and 1 yr. Repeated maternal, but not single ma ternal or fetal, betamethasone injections prolonged gestation, reduced weig ht at birth and 3 mo, and was associated with low arterial pressure at 3 mo but not at 6 mo and 1 yr. Glucose metabolism was altered in all betamethas one treatment groups, regardless of the number or route of injections. Our data demonstrate that glucocorticoid-induced fetal growth restriction is as sociated with a transient reduction in postnatal arterial pressure, but glu cocorticoid exposure with or without growth restriction alters glucose meta bolism.