The Importance of Iron in Pregnancy
Approximately 25% of people in the world currently have an iron deficiency, a condition which can be especially worrisome in pregnant people. In this blog post, I’m going to talk about what iron is and why it’s so important during pregnancy, how to keep iron levels up in early pregnancy, and what to do if you’re diagnosed with low iron in your 2nd or 3rd trimester.
So, what does iron do anyway?
You probably learned in school that your red blood cells are what carry oxygen to the other cells in your body so that those cells can remain alive and functioning how they should. Without oxygen, our bodies couldn’t move, think, react, or live! Iron is one of the key components of the molecule hemoglobin, which is basically the carrier car for oxygen inside red blood cells. This short video shows a 3D rendering of the hemoglobin molecule, and where iron and oxygen are connected to the molecule.
A single red blood cell can contain up to 300 million of these molecules, and your body has about 25 trillion red blood cells! That adds up to a lot of oxygen that can be carried in the body, but also a lot of iron needed to create all those hemoglobin molecules.
The problem with low iron in pregnancy comes from the fact that you’re not only trying to sustain your own life, but build a whole new one. During pregnancy, overall blood volume rises an average of 2000 mL (45% increase) to fill all the new blood vessels in the placenta. Your body also needs to increase your red blood cells by about 40% to carry enough oxygen for both you and your growing baby (Sanghavi & Rutherford, 2014). To support this increase in red blood cells, you need to be ingesting more iron than you ever have before.
Iron is not just needed to increase parental blood volume during pregnancy, but also to help build your baby. You need to be able to pass lots of iron to the fetus so they can start creating their own red blood cells, as well as develop their brain. Extreme iron deficiency has been shown to lead to decreased neurological development in infants and young children (Pavord et al., 2012), so it is vital for pregnant people to consciously increase their iron consumption.
Building good iron habits in early pregnancy
During the first trimester of pregnancy it can be difficult to build good eating habits because of the nausea that accompanies most pregnancies. You may be relieved to know that the biological need for iron doesn’t start kicking into high gear until the 2nd trimester. Once the nausea starts passing, however, it’s a great time to start incorporating extra iron into your daily diet to avoid a diagnosis of low iron as your pregnancy progresses.
Adding iron-rich foods to your diet is the easiest way to support your body’s iron stores (Health Canada: Iron). Meat / fish products tend to have the highest concentrations of easily absorbed iron, such as:
Beef, lamb, pork, or veal, especially liver or liverwurst sausage
Chicken, turkey, or other poultry
Eggs
Fish and seafood (although avoid tuna, halibut, king mackerel, and other fish high in mercury)
If you’re like me and a vegetarian, or just don’t love meat, fear not! You can still get lots of iron from plant-based foods, including:
Beans, lentils, peas, soybeans
Tofu and tempeh
Most meat alternatives like burgers, sausages, and chicken tenders are iron-enriched
Asparagus, broccoli, and cabbage
Spinach, kale, and other dark leafy greens
Enriched grain products like breakfast cereal and pasta
Pumpkin, sesame, flax, and hemp seeds
Dried apricots, prunes, raisins (21 Vegetarian Foods with High Iron)
Another nifty way to get iron in your diet that I just learned about is an iron fish! These little cuties can be popped into soups, curries, pastas, and teas while they’re cooking, and iron will seep into your food as you’re preparing it (Iron Fish Use). Unless you boil your fish for longer than 10 minutes, it won’t affect the taste of your food, and it’s 100% vegan! An iron fish can provide that additional nutrient boost you’ll need while pregnant, and can be easily added to nausea-friendly meals like chicken noodle soup or ginger tea to get you started on the right path even in the first trimester.
I’ve been diagnosed with iron deficiency… What are my options?
1. Oral Iron Supplementation
Your care provider will probably recommend iron pills as a first attempt to fix an iron deficiency. These pills are pretty easy to take, and depending on what your current iron levels are, you may only need to take one every other day. Do not take iron supplements at the same time as other medications or antacids, and take them at least 1 hour before a meal.
Most people say to take iron pills with a glass of orange juice or other high vitamin C juice to maximize absorption. However, a recent randomized control trial found no difference in iron levels in women who took their iron supplements with orange juice, and those who took them without (Li et al., 2020). While I hope this study will be replicated to see if future results match, it’s really up to you at this point. There’s definitely no harm in taking your pills with OJ, but you might not need to if you don’t want to.
It’s important to be aware that oral iron supplements can have some pretty unpleasant side effects. Nausea is common, as is constipation. You might be a little freaked out if you notice your bowel movements have a green tinge and a sandy consistency, but that is also a common side effect. For some people, these side effects are so bad they have to stop taking the pills.
2. IV Iron Infusion
The second option for people diagnosed with iron deficiency is an IV iron infusion. This is done like any other IV procedure, but it helps fortify your iron levels for a long period of time, so you’d likely only have to have it done a few times before delivery. IV iron has been shown to boost iron levels quicker and more effectively than oral iron (Govindappagari et al., 2021), and is a great option if you have very low iron, or you’re close to delivery.
While IV iron doesn’t have the persistent gastrointestinal side effects of oral supplements, it isn’t perfect. The actual process of receiving the IV might be kind of uncomfortable, and it usually takes an hour or so to complete. After your IV, you might feel like you have the flu - lethargic, bloated, or lightheaded, but these symptoms usually resolve in a few days. Rarely, IV iron can result in anaphylaxis (Cleveland Clinic: IV Iron).
If you’re going in for your IV iron infusion soon, remember to drink lots of water in the 24 hours before the procedure (top tip from a friend who’s had many iron IVs before).
Overview
To recap, iron is an incredibly important nutrient during pregnancy to support increased blood volume and to help the fetal brain develop. You should consciously increase your iron intake while pregnant by eating foods high in iron or using an iron fish. If you are diagnosed with iron deficiency in your 2nd trimester, you may be advised to take an oral iron supplement, which could have side effects like nausea and constipation. If you are unable to take the oral supplement, you will likely need IV iron, which can make you feel like you have the flu for a few days, but is very effective at increasing iron levels quickly.
If you have any further questions about keeping iron levels up during pregnancy, or how to deal with a diagnosis of low iron, feel free to message me!
Much love,
Sasha
