Abstract

Calcific incrustations of the primary internal elastic membrane in the common and internal iliac arteries could be shown grossly by a modified Von Kossa reaction in one-half of all necropsied newborns and infants in the first 4 weeks of life. The calcium content of the Von Kossa positive lesions was verified by Voigt's technique. After the age of 1 year calcific deposits were found in nearly every case. It is unlikely that resorption of these early calcific deposits occurs with growth.

The early development of calcific incrustations in the common and internal iliac arteries is obviously related to their position and function in the fetal circulation, i.e. to the higher haemodynamic load which results from the rapid increase in blood flow to the placenta during fetal development, and is associated with an accelerated growth and widening of both vessels.

In both iliac arteries only the well-differentiated, thick primary internal elastic membrane becomes calcified in childhood. This membrane is not present throughout the circumference of these arteries, but is developed in certain sectors only. Hence, the predilection site of the calcific incrustations, as well as their gross and microscopical patterns, is determined by the structural peculiarities of both iliac arteries, i.e. by the heterogeneous differentiation of the elastic elements in the vessel's tube. The significance of this heterogeneous structure for the development of later atherosclerotic lesions is still to be evaluated.