CIRCULATION DURING PREGNANCY

Abstract

The studies reported here deal with some of the alterations which take place in the maternal circulation during pregnancy. The first part of the report deals with observations bearing on the work of the heart during pregnancy and is particularly concerned with the cardiac output, the second part describes certain physical signs reflecting the state of the circulation, the third part reports a study of the venous pressure in the pregnant woman, the fourth part deals with certain related observations on animals and the final section discusses some of the mechanisms which underlie the phenomena observed. A discussion of the more general aspects of the problem has been presented elsewhere. 1 I. THE OUTPUT OF THE HEART AND SOME RELATED OBSERVATIONS Although the earlier literature concerned with the circulation during pregnancy contains many statements to the effect that the amount of blood pumped by the heart must be increased, the