During your pregnancy a number of changes will take place that serve to increase the delivery of blood to your unborn child. These changes are important in maintaining a healthy pregnancy.
Increase in the amount of blood in your body
During pregnancy, there is an increase in the amount of blood in your body (medical term: blood volume). The amount of blood increases by about 25%. Blood flow also increases too many parts of your body. This allows more blood (nourishments) to be delivered to the unborn child. However, this extra blood can be difficult for your heart to handle if the heart muscle is weakened weak or if the heart valves do not work properly.
Increase in the amount of blood the heart pumps
During pregnancy, there is an increase in the amount of blood the heart pumps to the body and the unborn baby (medical term: cardiac output). This allows more blood (nourishments) to be delivered to the unborn child. However, if your heart muscle is weak or if your heart valves do not work properly, then it may be difficult for the heart to pump extra blood to the baby.
Increase in your heart rate
The normal heart beats at about 60-90 beats per minute. During pregnancy there is an increase in your heart rate by about 10-20 beats per minute. This increase can be difficult for women with heart valve problems.
Drop in blood pressure
There is a drop in blood pressure early in pregnancy. The blood pressure begins to increase again at the end of the pregnancy. In general a lower blood pressure does not cause problems for women with heart disease. Occasionally, it can cause problems for women with holes in the heart who also have low oxygen levels.