ABSTRACT
During healthy human pregnancy, the peripheral circulation of the mother undergoes profound vasodilatation. Cardiac output increases by 50% secondary to the fall in peripheral vascular resistance (Figure 13.1), Combined with an increase in circulating blood volume these changes are geared towards increasing blood flow to the developing fetus. Blood flow to several maternal organs also increases dramatically during pregnancy. For example, blood flow to the kidneys goes up by 80%, to the skin of the hands and feet by over 200%, and most importantly, to the uterine arteries by 1000%. Conversely, blood flow to the maternal liver does not change, whilst that to the brain actually falls. Unravelling the mechanism of these widespread, but heterogeneous vascular changes in human pregnancy has proved challenging.
