Why Iron Levels Drop in Pregnancy (and What You Can Do About It)

Pregnancy is a magical, transformative time — but it’s also a season when your body is working harder than ever to nourish not just you, but the tiny life growing inside you. One common challenge many women face during pregnancy is low iron levels.Let’s dive into why this happens, what it means for you and your baby, and how you can support your iron levels naturally and safely.

Why Do Iron Levels Decrease in Pregnancy?

During pregnancy, your body increases its blood volume by about 50% to support your growing baby. That’s a lot of extra blood! Iron is essential to produce hemoglobin, the protein in red blood cells that carries oxygen. So naturally, your iron needs ramp up too — almost doubling by the third trimester.

On top of that:

• Your baby is also building their own iron stores for the first six months of life.

• The placenta itself needs iron to grow and function properly.

Because of all this, even women who start pregnancy with healthy iron levels can find themselves running low by mid-pregnancy.It’s not just about eating more iron — your body is trying to do a lot, and it can sometimes struggle to keep up!

How to Increase Your Iron Naturally

The good news is there are plenty of ways to boost your iron stores — and food is one of the best places to start.

1. Focus on Heme Iron (Animal Sources)

Iron from animal foods (known as heme iron) is much better absorbed than iron from plant foods (non-heme iron).

• Sources of heme iron: Beef, lamb, chicken, turkey, liver

• Absorption rate: About 15-35% of heme iron is absorbed, compared to only 2-20% from plant-based sources.

Plant foods like spinach, beans, and fortified cereals contain non-heme iron, which is trickier for the body to absorb — especially if your digestive system is already sensitive during pregnancy.

💡 Tip: If you’re eating mostly plant-based, pair your iron-rich foods with vitamin C (like oranges, capsicum, strawberries) to help boost absorption!

2. Spotlight on Superfood: Beef Liver

If you tolerate it, beef liver is truly a pregnancy superfood.

• It’s one of the richest sources of highly absorbable heme iron, plus it provides vitamin A, B12, choline, and folate — all critical for your baby’s development.

• Small amounts (like 50–100g once or twice a week) can work wonders for your iron stores.

• Note: Because liver is very high in vitamin A, moderation is key. Chat with your nutritionsit about how to safely include it in your diet.

Bone broth is another beautiful traditional food to support you during pregnancy.While not super high in iron itself, it’s incredibly nourishing for your gut health — and a healthy gut means better nutrient absorption, including iron.Bone broth also provides collagen, gelatin, and minerals like calcium and magnesium — soothing and strengthening your body from the inside out.

🌿 Incorporating these traditional foods can gently and naturally support your iron levels — and they’re comforting to sip on, especially if you're feeling a bit queasy!

3. Consider Iron Supplements (But Choose Wisely)

Sometimes, diet alone isn’t enough — especially if your levels are already dropping.This is where supplements can help, but not all iron supplements are created equal!

• Synthetic iron (like ferrous sulfate) is the most commonly prescribed, but it's poorly absorbed and can cause side effects like constipation, nausea, and stomach upset.

• Gentler forms like iron bisglycinate are often better tolerated and better absorbed.

• Some high-quality pregnancy multis contain smaller, more easily absorbed doses of iron to help maintain levels without overwhelming your gut.

👉 Important: Always chat with your nutritionist before starting supplements. Too much iron can be harmful, and it’s important to tailor the dose to your needs.

When to Supplement (And When to Test)

It's important not to self-prescribe iron "just in case." Both too little and too much iron can cause problems.

Testing is key to knowing what your body actually needs.

In pregnancy, iron studies are usually checked:

• Early in pregnancy (first trimester bloods)

• Around 26–28 weeks (alongside gestational diabetes screening)

• If you have symptoms like fatigue, dizziness, breathlessness, or if there are other concerns.

I often test my clients more often than the above, to stay on top of it. I usually focus on building iron stores prior to pregnancy by including iron in preconception blood tests, then once in each trimester, and definitely postpartum.

Understanding Iron Blood Tests

It’s not enough to just check your "iron level" — we need to look at the whole picture.

A thorough iron panel usually includes:

• Ferritin: Reflects your iron stores (think of it like your savings account).

  • Low ferritin = low stored iron.

  • High ferritin can sometimes occur with inflammation or infection.

• Serum Iron: Measures circulating iron at the time of the test.

• Hemoglobin (Hb): Shows how much oxygen-carrying capacity your blood has.

  • If your Hb is low, you could have anemia.

• Red Cell Count (RCC) and MCV (Mean Corpuscular Volume):These show the size and number of red blood cells.

  • In iron deficiency, red cells often become smaller (low MCV) and fewer in number.

🩺 Why all these tests?Because sometimes ferritin can look "normal" but your red blood cells and hemoglobin tell a different story. Testing gives us the clearest view of what's really happening and helps guide the best treatment plan.

⚠️ A Note on Iron Infusions: Helpful or Harmful?

Iron infusions can be a helpful option when iron levels are critically low, or if oral supplements aren’t tolerated — especially later in pregnancy when there's limited time to rebuild stores. However, they’re not without risks and shouldn’t be the first line of treatment unless absolutely necessary.

Here’s why we use them with caution:

• Infusions bypass the gut, which means your body doesn’t get to regulate absorption in the natural way it would with food or oral supplements.

• They can cause oxidative stress in the body, contributing to inflammation and affecting the delicate balance of your immune and gut health.

• In rare cases, infusions can lead to allergic reactions or long-term iron overload, which can damage organs if not carefully monitored.

For many women, iron levels can be gently and effectively restored through food, gut support, and well-tolerated oral supplementation — without jumping straight to intravenous iron.

💛 Iron infusions have their place, but they should be used as a thoughtful, targeted tool — not a quick fix. Always ask your care provider: “Is this truly necessary, or can we try another approach first?”

The Take-Home Message

It’s completely normal for iron demands to rise in pregnancy — but low iron isn’t something to ignore.Low iron can affect your energy, your mood, your immune system, and even your baby's growth.

By:

• Eating iron-rich foods (especially heme iron from meats and liver)

• Supporting digestion with traditional foods like bone broth

• Choosing gentle, absorbable supplements when needed

• Testing at the right times

• Working closely with your care team

...you can keep your iron levels strong and support a vibrant, thriving pregnancy.

You’re doing an incredible job growing this little human — and you deserve to feel strong, supported, and nourished along the way. 💛

Concerned about your iron levels? Book here for customised advice