The primary objective of this study was to demonstrate shifts of plasma between vascular and extravascular spaces during the first 2½ hours of life. Such shifts in plasma volume have been postulated by Marks et al. in order to account for the significant rise in packed cell volume that they demonstrated within the first 2½ hours of life.1 Plasma volume was measured by human serum-albumin-bound iodine131 (Risa, Abbott Laboratories). Since, to date, this agent has not been used for this purpose in newborn infants, a demonstration of its effectiveness was the second major objective. A third objective of this study was to relate the early changes occurring in the blood compartments to the pathogenesis of hyaline membrane disease. For this purpose, infants born by Cesarean section were compared with infants born by normal vaginal delivery.
Materials and Method
Nine normal newborns and 9 elective Cesarean section infants were