We’ve talked a little bit about how pregnancy changes blood circulation within a woman’s body as it compensates for the baby’s growth. We thought we’d take a moment to elaborate a little bit more on how fetal and maternal blood circulation works during pregnancy, but more importantly how the discomforts and complications associated with these changes can be reduced, avoided or minimalized by understanding these processes a bit better.
When a woman becomes pregnant, her blood volume can increase anywhere from 30-50%. The blood itself changes during pregnancy, wherein the amount of plasma increases considerably in red blood cells. This increase in volume and plasma normally peaks around the 24th week of pregnancy and begins to drop to more normal levels around the 30th week. Blood levels increase once more during delivery, and then subsequently drops again when blood is lost during birth. Much like blood volume, blood pressure also tends to drop during the second trimester and then rises again in the third.
As mentioned above, this increase occurs to compensate for the growing fetus. During pregnancy, a mother’s arteries supply the placenta with oxygenated blood through the umbilical cord to the fetus. There, the fetus strips the blood of nutrients and oxygen, sending the ‘waste’ blood back into the mother’s circulatory system to the lungs to become oxygenated again. Pretty cool.
These massive circulatory changes to a pregnant woman’s body can often create discomfort and/or complications, the majority of which disappear or reduce after birth. Some discomforts can include swelling and increased pressure to the lower extremities as a result of the increase blood volume output. Low blood pressure and high blood volume can also cause extreme fatigue, headaches and sometimes even hemorrhoids. Complications related to circulatory changes can also occur. Intrauterine growth restriction (also known as IUGR), which hinders optimal fetal growth, can be caused by several problems stemming from defects associated with the placenta or umbilical cord, and especially if the mother-to-be has poor circulation. Complications associated with circulatory problems during pregnancy can also cause the mother to develop preeclampsia, dangerously high blood pressure and possibly anemia.