When the tiny drop of blood from your finger is put into the machine, it measures the amount of hemoglobin per red blood cell. Hemoglobin is the iron containing protein in red blood cells that transports oxygen. Knowing this number can tell you how well your body is transporting it's oxygen, which is important to your growing baby.
If it is early in pregnancy (say around 12 weeks), you want to have a healthy amount of hemoglobin, 12.5 or higher. The reason it is important to have a good amount now is because in the last trimester of pregnancy, normal physiological anemia is expected. As the third trimester begins, the plasma in the blood expands at a quicker rate than the red blood cells, so your hemoglobin is diluted. The expected drop in late pregnancy is 2 grams, so if you started at 12.5, you'd be at 10.5 in late pregnancy.
The most commonly used limit for diagnosing anemia in pregnancy is 10 and there can be several causes for anemia. We've already covered the normal physiological anemia, so the other causes of anemia can include iron deficiency, folate deficiency, Vitamin B-12 deficiency, or diseases such as Sickle Cell, Thalassemia, chronic disease, or acute blood loss.
Approximately 95% of anemia in pregnancy is caused by iron deficiency. Since hemoglobin is made up of iron, it is necessary for healthy blood oxygen transport. Folate (folic acid, a B vitamin) deficiency can happen when the diet is low in folate, which is also required for producing red blood cells. It is found in dark leafy greens. Vitamin B-12 deficiency is more common among vegans since it is found in meat, fish, poultry, milk and eggs.
Since most anemia is caused by iron deficiency is caused by a lack of iron in the diet, usually iron pills are prescribed by the doctor. Iron can also been increased in the diet by eating things that have a lot of iron. "Heme" source of iron are those that come from something containing hemoglobin and include red meat, poultry - especially the dark meat - fish and seafood. "Non-Heme" sources of iron are less easily absorbed by our bodies, but provide most of the dietary iron. These include dried fruit, iron-fortified cereals, breads and pastas, whole grains, blackstrap molasses, spinach, kale, collard greens, and other dark leafy greens, baked potatoes with the skin, beans, peas, nuts and seeds.
Our bodies do not absorb all of the iron we eat. In fact, it only retains 10-15%, but the rate of absorption is tied to the amount our bodies need. If our iron stores are low, we will absorb more iron from the foods we eat. Coffee, tea, wine, soda, milk and calcium can all decrease the rate of iron absorption, while foods containing Vitamin C can help us absorb more iron.
Having this understanding of anemia in pregnancy can help you to check your diet to make sure you are getting what you need to grow a happy healthy baby!