Response of fetal adrenal cortex to congenital infections

Plasma corticoid levels and changes in adrenocortical morphology were studied in fetal and neonatal lambs infected with one of 3 agents capable of causing congenital infection. The agents, Brucella ovis, Border disease, and/or rubella vaccine virus, were introduced by intrafetal inoculations at different stages of fetal development. Heparinized blood was collected from fetal and neonatal lambs and their ewes prior to the time they were killed, and adrenals were then saved for histologic evaluation. Values obtained from infected lambs were compared to those of heparinized samples collected daily for 3 weeks prior to birth via a catheter from 3 control lambs. Precocious adrenocortical activity measured by both morphologic and physiologic parameters was observed in lambs infected with these agents after 130 days of the 148 day gestation period. In 2 instances, the increased adrenocortical activity was associated with premature delivery. Congenital infection with these 3 agents appears to result in fetal stress.