Important: This is intended as general information only. It may not apply to your specific situation. It is not a substitute for medical advice. If you have a question or concern, please raise it with me at your next appointment or contact me sooner if it's urgent.
Anaemia and Iron Deficiency in Pregnancy
Anaemia in pregnancy is very common. Anaemia means that you have a lower than normal number of red blood cells. Although there are many causes of anaemia, by far the most common (especially in pregnancy) is iron deficiency. We need iron to make haemoglobin, which is the molecule in red blood cells that is responsible for transporting oxygen around the body.
In pregnancy, your daily requirement of iron goes up sharply. Nonpregnant women require 18mg per day while pregnant women require 27mg per day. This is, essentially, because the baby requires iron and raids your iron stores (while your body bravely sacrifices itself).
As well as the baby’s need for iron, anaemia can make you feel breathless and lethargic and cause your heart to race. In addition, everyone loses some blood at delivery (regardless of the mode of delivery). Most women lose only a small amount and are fine, but a small amount of women lose a larger, more concerning amount. If we make sure that you have a nice high red blood cell level before delivery, it builds in a bit of a safety buffer – you can afford to lose more blood before it becomes a major issue.
I will monitor your haemoglobin level (blood count) and ferritin level (your iron stores) throughout the pregnancy. If either of these drops significantly, you may require iron supplements. These can be given in a few different ways – liquid, tablets, intramuscular injections or intravenous infusions. There’s no real difference in the types of iron – iron is an element like oxygen or gold so any two atoms of iron are the same. However, the different formulations allow us to give different doses. We usually start with tablets. If you have trouble taking these (they can cause nausea and constipation) and your iron levels aren’t too bad, it may be possible to take the liquid iron. People usually find the liquid iron a bit easier to tolerate, largely because the dose you end up getting is smaller. If we can’t get your blood count and iron levels up with oral medication, we may use intramuscular or intravenous iron – this allows us to give a larger dose and doesn’t cause stomach upset.
While a diet rich in iron is certainly good for you, most pregnant women can’t significantly increase their iron levels with diet alone. Foods that are high in iron include red meats, cereals, leafy green vegetables and pulses.
Your pregnancy multivitamins do contain some iron but the dose is not adequate for women who are already iron deficient. Even if the dose written on the side of the packet looks reasonable, the various other thing in the tablet compete with iron (and each other) for absorption so the dose is often not as good as it might look.
Various other, much less common, conditions can also cause anaemia. They are too numerous and complex to cover here but I will discuss them in detail with you if you encounter any of them during your pregnancy.