The blood flow in the placenta and cardiac output during pregnancy.

Approximately 625 ml of blood pass through the mother's circulation to the placenta every minute in the last month of pregnancy. This and the general boost in the metabolism of the mother increases the cardiac output of the mother at 30 to 40 percent above the normal of the 27th Week of pregnancy, and then for unknown reasons, cardiac output falls only slightly higher than normal in the last eight weeks of pregnancy, in spite of the high uterine blood flow.

Blood volume during pregnancy.

The volume of maternal blood, just before the deadline is about 30 percent higher than normal. This expand happens primarily during the last half of pregnancy. The reason for the increase in volume is likely at least partially, aldosterone, and estrogen, which increases significantly during pregnancy and the increase? Uid retention by kidneys.Also, bone marrow is actively producing RBC to go further, to excess? uid volume. Thus, if the baby is born, the mother has approximately 1 to 2 additional liters of blood in his circulatory system. Only around a quarter of that amount is generally lost via bleeding during the birth of the child, so that a factor of safety for the mother.