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Pregnancy Jul 19, 2020
10 Minutes

Iron: 50% of us deficient?!

It goes without saying that during pregnancy you need more of the good stuff: nutrients. Iron is a major nutrient that plays a huge role in all important things like increasing red blood volume, supporting the growing baby, placental and neurological development. Plus of course, preparing the body for birth. Like many things we need more of it during pregnancy. Did you know however that during pregnancy many of us end up deficient? This can have consequences for our own health as well as our baby, particularly if it turns into anaemia. We take a look at the key things you need to know. What it is, when it is a problem, how you know it’s a problem and most crucially how to treat and avoid!

Make sure you are regularly checked: 

Many doctors will check your red blood cell count, Hemoglobin (the protein within our blood cells) and other assorted markers to ensure you are not anaemic or have a possible iron deficiency. However, it is up to you to ensure that these checks are done regularly through your pregnancy. Particularly in our tricky times. Make sure you don’t fall through the cracks!

One study suggested that over 50% of iron deficiency gets missed. (1) We also know that iron deficiency and iron deficiency anaemia are common during pregnancy with an estimated prevalence of 30-50% for iron deficiency and 15-20% for iron deficiency anemia. (6

Why is it so important to stay on top of your iron and to prevent anaemia during pregnancy? 

Firstly, you do not want to deplete your all important iron stores as more is required through pregnancy and breastfeeding. Secondly iron deficiency can lead to anaemia. As above, is not entirely uncommon in pregnancy.

Iron deficiency

Iron deficiency anemia is the most common form of anaemia during pregnancy. Essentially it is where your iron intake is not sufficient to meet the body’s requirement to produce red blood cells. (5

First and foremost, the good news is that many studies show the body is smart. Your unborn baby will be prioritised when it comes to getting the ‘good stuff’ and what is needed. Particularly when it comes to iron. (5).


What about if your own iron needs are not met? 

Despite our main focus during pregnancy being the baby, you also matter! Particularly for the health of your pregnancy. If you are deficient then it can have a knock on impact. If your iron intake is low, and the baby is prioritised you will deplete your all important iron stores.

Iron deficient anemia can lead to increased risk of C Section, perinatal bleeding, preeclampsia, issues with the placenta (abruption), infection and impaired wound healing. It has also been connected to Thyroid issues (more to come on this). All things you don’t want for a healthy pregnancy. (1, 4, 7)

In fact, anemia in pregnancy (which can be a consequence of not enough iron) has been said to lead to twice the chance of preterm labour and three times the chances of low birth rate. (1

The positive: getting enough iron can help with your baby’s brain development: 

Many studies have shown that getting enough iron is a positive for cognitive development. Research has increasingly suggested that Delayed Cord Clamping (click here for much more) which means boosting the baby’s own iron storage has been linked to improved neurological development and immunity. 

Preventing iron deficiency in your baby: 

At birth babies have around a 75mg/kg store of iron. With delayed cord clamping they receive an additional 40mg or iron at 1 minute and 50mg at 3 minutes. That is ‘enough to prevent iron deficiency in the first 6 months of life and probably until a year old. (8). 

Obviously the key is having enough iron yourself for this to be optimal! 

So how much iron do you really need during pregnancy? 

Not all prenatal vitamins contain Iron – as not everyone will need extra support. Once again this is why regular monitoring with your doctor is so important! 

In terms of some numbers: a normal pregnancy consumes 500-800mg of iron from the mother. Your requirements go from around 0.8mg/day up to 7mg/day increasing as your pregnancy processes. (5)

So where do we get it from? 

The body is much more able to absorb what’s known as heme iron which comes mainly from animal products such as lean red meat, chicken etc. Leafy green vegetables or fortified breakfast cereals (non-heme iron) makes up a smaller amount of your iron intake as it is harder for the body to absorb. (5) 

How can you tell if you have iron deficiency/anaemia? 

As above, Iron deficiency won’t immediately cause anaemia. Anaemia can be a consequence of iron deficiency (or other things) so once again ensuring you have enough to meet increased needs during pregnancy is key.

The symptoms of iron deficiency and iron deficiency anemia can also be vague. They can be everything from fatigue and shortness of breath (common in pregnancy) to headaches, brittle nails, dizziness and restless leg syndrome. (3

That is why the best way to keep on top of this is regular blood tests with your doctor. 

So if I have low red blood cell count it means I have anaemia?! How to interpret your blood test results: 

This is where your doctor will help explain and interpret the different between ‘dilution’ vs anaemia.

The thing about pregnancy is naturally your blood volume naturally expands. That can mean as a percentage of volume your red blood cell count will go down. This is known as ‘physiologic anemia’. There are major benefits to this blood volume expansion, such as enhancing the passage of blood through the placenta and facilitating oxygen and nutrient delivery to the baby. (5). 

In fact, during nearly all pregnancies you could see a Hemoglobin level (the protein in your red blood cells) go as low as 10g/dl with the ‘majority of cases reflecting a physiologic process rather than a deficiency state or underlying disorder.’ (5

So when should you be concerned? 

Your doctor will be the one checking through your results so don’t worry. However, here at The Journey we are big on empowering you with knowledge too. We think it’s important for you to understand where you’re at which some time poor doctors may not explain. 

What to look for on your test results: 

There are different definitions of potential iron deficient anemia as your pregnancy progresses.

If you are below these levels your doctor may ask for further tests to really get to the bottom of what’s going on:


What happens next if your doctor suspects iron deficiency could be leading to anaemia during your pregnancy? 

Depending on severity of course, first port of call is likely to be oral iron supplements. You’ll likely be asked to have a repeat test in a few weeks to see how you react. The good news is that routine iron supplementation has been shown to reduce the frequency of anaemia in pregnancy by almost 75% (5). Easy business!

‘In general, iron supplementation is considered low risk and an iron supplement of 65mg elemental iron per day beginning at 20 weeks gestation is adequate to prevent iron deficiency during pregnancy.’

Watch out for these iron absorption traps! 

The best way to absorb your iron is on an empty stomach as gastric acid is needed to break it down into amino acids. Even better is if you have it alongside some Vitamin C. This protects the elemental iron allowing it to pass to the right places for absorption. (1) Not everyone wants to drink a glass of orange juice due to the sugar content but a green juice will also give a helping hand. Particularly if there is kale, lemon or grapefruit in there.

Things to avoid around taking your supplement: Tea or coffee or anything that contains tannins. Research has shown that this can limit absorption. So avoid for a couple of hours after your supplement. (2) Similarly Phytic Acid (often found in things like oats/grains/cereals) have been shown to block iron absorption. (2) An easy solution? Soak them overnight before.

However, a supplement may not always work…. 

If you are severely deficient or do not react well to oral supplements (they can cause some gastric discomfort, constipation or diarrhoea) your doctor may recommend an IV.

The good news about iron replenishment with IV: 

The new formulations are safe and effective and are something your doctor may suggest in the second and third trimester to quickly restore your iron levels. (1)

What follow up tests may you ask for/your doctor may request:

If you’re not responding as expected or your levels are particularly low your doctor may also take a look at your serum ferritin (which shows your iron stores – ideally you want above 30 micrograms/litre). He or she may also look for inflammation (C Reactive Protein) and may also check your folate/vitamin B levels. Low levels of these B vitamins can also contribute to Anaemia. This will be to check there are not other reasons for deficiency or anaemia.

The curve ball: Thyroid… 

In the more recent past there has been investigations done into the link between your Thyroid and iron deficiency. It can seemingly impact absorption of iron or on the flip side it appears that iron deficiency can impair thyroid metabolism itself. (4). Thyroid dysfunction is a ‘common endocrine disease during pregnancy’ (7).

‘Growing research suggests that iron deficiency with or without anaemia impairs thyroid metabolism.’ (4) Although at this point the mechanism is not totally clear.

The Thyroid is a crucial hormone producer for life in general but particularly for pregnancy and for a baby’s development. Once again ensuring your thyroid is checked regularly throughout pregnancy is key. Don’t be afraid to speak up and ask for checks.

Hidden Thyroid issues… 

Once again a blood test is the only reliable way to check, particularly as we have incidence of what is known as subclinical Thyroidism. This is where effectively you have no real symptoms and your results can be within the range of ‘normal’. Click here for more. 

Thyroid levels fluctuate during pregnancy however ATA guidelines suggest that keeping TSH 2.5mU/L and below is ideal (vs the upper recommended limits of 4.0) and checking for Thyroid Antibodies which are often not screened for unless asked. This is particularly important if you’ve suffered miscarriage or infertility in the past.

The key thing to remember is once we know about issues they can be treated and you can be on your way.

Bottom line: what do we really need to know about iron during pregnancy? 

As you can see, it’s important that our increased needs are met. This will give a helping hand towards a healthy pregnancy and baby. As well as protecting you.

You do need more during pregnancy and the most effective forms are from heme-iron sources: animal products. Non-heme sources are less absorbed so vegetarians/vegans may want a supplement.

Oral supplements are pretty effective but to ensure you’re getting the most out of it take with Vitamin C and on an empty stomach. Even better avoid tea/coffee a few hours after before/after. Any grains should be soaked to eliminate phytic acid which can also impact absorption.

If you are deficient a blood test will tell you. You may be on oral or IV supplements and if things don’t improve your doctor may do other follow up tests to establish the root cause. Including checking your Thyroid, Inflammation and your B Vitamin status.

Ultimately ensuring you have enough iron and prevent anaemia can go a long way to helping your pregnancy and your baby’s development. It is just about regular checks and knowing what to look out for.


1) Auerbach M: Iron Deficiency of pregnancy – a new approach involving intravenous iron: Reproductive Health: 2018 15 (1) 96 

2) Delimont N,  Haub MD, Lindshield BL: The impact of Tannin Consumption Iron Bioavailability And Status: Oxford Academic Current Developments in Nutrition: Feb 017 

3) Auberbach M, Adamson JW: How we diagnose and treat iron deficiency anaemia: American Journal of Haematology: Sep 2015 i

4) Li S, GAO X, Wei Y, Zhu G, The relationship between Iron Deficiency and thyroid Function during early Pregnancy: Journal of Nutritional Science and Vitaminology: 2016 Vol 62 (397-401)

5) Means RT: Iron Deficiency and Iron Deficiency Anaemia : Implications and Impact i Pregnancy Fetal development, and Early Childhood Parameters: MDPI Nutrients 2020 Feb 11;12(2); 447

6) Wiegersma AM, Dalman C, Lee BK, Association of Prenatal Maternal Anaemia  With Neurodevelopmental Disorders: JAMA Psychiatry: September 2019

7) Yang Y, Hou Y, Wang H, GAO X: Maternal Thyroid Dysfunction and Gestational Anaemia Risk: Meta-Analysis and New Data: Frontiers in Endocrinology: April 2020. 

8) Fogarty M, Osborn DA, Askie L, Seidler AL, Hunter K: Delayed vs Early Umbilical Cord Clamping for preterm infants: A systematic Review and Meta-Analysis: American Journal Obstetrics and Gynaecology: 2018: Jan; 218(1): 1-18



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