I could hear my patient’s labored breathing even before I entered the room. Her short, ragged breaths were as stressful to me as they were painful to her. I couldn’t understand it. I was her obstetrician: She saw me every week for her pregnancy and I couldn’t solve, let alone fix, this problem. She was in her early third trimester of pregnancy, had no complications and no medical condition to explain this shortness of breath.
I had referred her to cardiology and pulmonology, wondering if the pregnancy challenge was uncovering an underlying medical problem such as pregnancy-induced heart failure. He passed every test and no diagnosis was made. However, he was still struggling to catch his breath. I reexamined her labs. She was mildly anemic – but nothing significant enough to explain this persistent shortness of breath. Or could it?
A laissez-faire attitude towards anemia
As an OB-GYN, I often hear patients casually remark, “Oh, I’ve always been anemic,” when reviewing their blood work. In the past I did not take this dismissal very seriously, but now I find the attitude indifferent. This casual approach to iron deficiency anemia (IDA) reflects what patients hear from their doctors: that it is common, harmless, and nothing to worry about.
However, my patient experiences have taught me that this view is inaccurate and potentially dangerous. Why? Because iron deficiency—having too little iron in your body—is more than a minor inconvenience. It is the most common nutritional deficiency worldwide and can have serious health effects, especially during pregnancy.
Iron Deficiency vs. Anemia: What’s the Difference?
One of the first steps in understanding iron deficiency anemia is to recognize that anemia, simply defined as the pallor of red blood cells, is a symptom of a disease, not the disease itself. The disease is iron deficiency. Here’s what’s under-recognized: Iron deficiency is the root cause of the problem.
Iron deficiency refers to low amounts of stored iron in the body,5 whereas iron deficiency anemia is simply the body’s way of proving that it has low iron stores. An example of this is pregnancy, during which a woman’s iron stores are strained by the demands of the growing baby. The level of anemia may not be severe – but iron stores are working hard in so many other functions that these levels begin to drop and symptoms may appear that do not correlate well with the small level of anemia seen in the blood tests.
Why iron matters
Iron is used by the human body in hundreds of biological processes. Iron is essential for our growth and survival. Just a few of the important processes where iron is necessary include: making DNA, transporting oxygen, and giving the body the ability to generate needed energy.
If we look at it this way, iron is one of the most important minerals the body needs to stay healthy. When you don’t have enough iron, you may experience:
- Fatigue
- Restless legs
- Unusual craving for non-food (pica)
- Heart palpitations (arrhythmias)
- Muscle weakness
- Anxiety or depression
- Difficulty concentrating6
For women, iron deficiency can also cause:
In pregnancy, iron deficiency can result in:
- Low birth weight
- Premature birth
- Slower growth of the baby in the womb (intrauterine growth restriction)2
What is of particular concern is that iron deficiency during pregnancy can lead to adverse effects on fetal brain development, potentially leading to learning disabilities or behavioral problems later in life.3
Therefore, during pregnancy, the main reasons for maintaining adequate iron stores are to protect your health, improve pregnancy outcomes and enhance your baby’s development.
Why women are at greater risk for iron deficiency
Of the nearly 2 billion people on the planet with iron deficiency, the disease mainly affects women.2 According to the WHO, 37% of pregnant women and 30% of women of reproductive age worldwide are affected by low iron levels.
Why are women so disproportionately affected? These are the three main factors of iron deficiency:
- Diet: Women may have a lower iron intake, especially if they are vegetarian or vegan
- Increased need: Pregnancy dramatically increases the body’s iron requirements
- Blood loss: Monthly menstruation leads to a regular loss of iron
Many women enter pregnancy already low in iron. Then, as the baby grows, the need for iron skyrockets: from 0.8mg per day in the first trimester, to 4mg per day in the second trimester, to 6mg per day in the third trimester!
How we test for iron deficiency is important
Despite its high prevalence, iron deficiency remains underrecognized by clinicians, primarily because screening guidelines from most medical organizations do not recommend screening for iron deficiency1 specifically, but rather focus on assessing anemia.
But by the time anemia occurs, you’ve already been iron deficient for a while.2 Most medical organizations recommend testing hemoglobin concentrations to screen for iron deficiency anemia. However, the WHO recommends using a test called ferritin to check iron levels. Ferritin is a more accurate way of testing for iron deficiency than hemoglobin.5
A personal lesson
Remember my pregnant patient with shortness of breath? After testing her ferritin levels, we discovered that she was indeed iron deficient. Once we gave her the iron her body needed, her breathing improved dramatically.
Basic foods:
- Iron deficiency is common, especially in women, but is often overlooked
- It can cause a wide range of symptoms and health problems, especially during pregnancy
- Standard anemia tests may miss iron deficiency – ask your doctor about ferritin testing
- Don’t dismiss iron deficiency as ‘normal’ or harmless – it’s a health issue worth addressing
By being aware of iron deficiency and its effects, we can take steps to improve the health of women, their children and all those affected by this common but serious condition.
References:
1. Abdulrahman, Al-Nadeem, Abdelrahman Sállame, Shamin Choudhury and Jecko Thachil, Clinical Medicine 2021 Vol 21, No 2: 107-113 “Iron Deficiency without anemia: a diagnosis that matters”
2. Michael K. Georgrieff, MD, American Journal of Obstetrics and Gynecology, October 2020. “Iron Deficiency in Pregnancy”
3. Sriparna Basu, Dinesh Kumar, Samoa Anupurba, et al. Journal of Perinatologists (2018) 38:233-239. “Effect of maternal iron deficiency anemia on fetal neural development”.
4. Robert T. Means. Nutrients 2020, 12, 447. “Iron Deficiency and Iron Deficiency Anemia: Implications and Impact in Pregnancy, Fetal Development, and Early Childhood Parameters.”
5. World Health Organization Summary: Use of Ferritin Concentrations to Assess Iron Status in Individuals and Populations 2024
6. Barton, James, et al. PLoS One 15 (4), e0232125 2020 Prevalence of iron deficiency in 62,685 women of seven race/ethnicity groups: The HEIRS study 7. Bothwell, American Journal of Nutrition 2000
This story is part of The Motherly Collective partner network where we feature the stories, experiences and advice from brands, authors and experts who want to share their perspective with our community. We believe that there is no single motherhood story and that every mother’s journey is unique. By empowering each mother’s experience and offering expert-driven content, we can support, inform and inspire each other on this incredible journey. If you are interested in contributing to The Motherly Collective, click here here.
