Circulatory Adaptation to Pregnancy - Serial Studies of Haemodynamics, Blood Volume, Renin and Aldosterone in the Baboon (Papio hamadryas)

To test the hypothesis that haemodynamic changes in pregnancy precede any significant increase in circulating blood volume, serial haemodynamic studies were performed in eight baboon pregnancies using Swan-Ganz catheterization and arterial cannulation. Simultaneous measurements were made of red cell and plasma volumes, and of plasma renin activity and aldosterone concentration. Haemodynamic changes identified by 4 weeks gestation included significant (P