The placental transfer of gases and fixed acids.

The possibility of obtaining intervillous blood from pregnant women has made it feasible to study the placental exchange of various substances. Those which are perhaps most vital, i.e. oxygen and carbon dioxide, have already been studied to some extent (Prystowsky, 1957, 1958, 1959, 1960; Prystowsky, Hellegers and Bruns, 1960; Walker, 1959; Sjostedt, Rooth and Caligara, 1960; Rooth, Sjostedt and Caligara, 1961b). It is the purpose of the present paper to give a more complete picture of the placental transfer by describing both the transfer of the blood gases and the fixed acids.