What changes take place in the composition of a pregnant woman's blood as it passes through the uterus and placenta?

During pregnancy, a woman's blood undergoes significant changes as it passes through the uterus and placenta. There is an increase in blood volume and a higher concentration of red blood cells to enhance oxygen transport to the fetus. Additionally, the levels of certain hormones, such as estrogen and progesterone, rise, which can affect clotting factors and immune response. Nutrients and waste products are exchanged between maternal and fetal blood, with the placenta acting as the vital interface for these processes.