[Maternal cardiovascular adaptation in pregnancy]

Maternal cardiovascular adaptations during pregnancy, such as cardiac output, blood volume, hormones, water and electrolyte balance, arterial blood pressure, vascular resistance, uterine blood flow amongst others ensure the well-being of the mother and of the fetus. Several of these changes are not yet well understood. This report reviews the factual changes in cardiovascular physiology during pregnancy. Methodological experimental problems are identified and their relationship to the interpretation of the data discussed. Open scientific questions are identified and the experimental designs necessary to answer them are discussed. The possible mechanisms which are responsible for these changes are addressed. Special attention is given to arterial blood pressure during pregnancy as the regulated variable. It is shown how cardiovascular parameters are involved in the regulation of blood pressure and the signals, which trigger these changes. The effects of the vasoactive agents, angiotensin II and catecholamines, on the circulation during pregnancy are reviewed. Alterations of baroreceptor function are discussed for this time period. Further investigations should assess venous function during pregnancy to elucidate mechanisms by which such maternal adaptations occur.