For weeks, I assumed my exhaustion was simply part of being pregnant.
By 7 p.m., I was often asleep. Getting through a normal workday felt harder than it should have, but pregnancy is tiring, so I kept treating it like something I was supposed to push through.
Then, at approximately 25 weeks, I learned that my ferritin had dropped to 8 ng/mL. Earlier in my pregnancy, it had been 23 ng/mL.
Even as a registered dietitian, seeing that drop caught me off guard. I knew iron needs increase during pregnancy. I knew low iron can cause fatigue. But living it felt very different from explaining it to a client.
My prenatal care team evaluated my complete clinical picture and recommended an iron infusion. Afterward, I noticed a meaningful improvement in my energy.
My experience is not proof that every tired pregnant person needs an iron infusion. Fatigue has many possible causes, and treatment decisions should be based on symptoms, gestational age, medical history and a complete set of laboratory results.
But I do wish more pregnant people understood what ferritin measures, how it differs from hemoglobin and why “your blood count looks fine” may not answer every question about iron status.
What Does Ferritin Measure?
Ferritin is a protein that stores iron. A ferritin blood test provides information about how much stored iron your body has available.
Hemoglobin is different. Hemoglobin is the iron-containing protein in red blood cells that carries oxygen throughout the body.
Iron deficiency generally develops in stages. Ferritin may drop first as stored iron becomes depleted. If the deficiency progresses, the body may eventually have less iron available for red blood cell production and hemoglobin may fall.
That means someone can have low ferritin before meeting the diagnostic criteria for anemia. Low ferritin and iron-deficiency anemia are related, but they are not interchangeable terms.
Ferritin also behaves as an acute-phase reactant, meaning inflammation can cause it to rise. This can make a normal or elevated ferritin result more difficult to interpret in certain situations. Clinicians may consider ferritin alongside a complete blood count and other iron studies.
Is a Ferritin Level of 8 Low During Pregnancy?
Yes. A ferritin level of 8 ng/mL is considered low under commonly used pregnancy thresholds.
According to a review of American College of Obstetricians and Gynecologists guidance, ACOG defines iron deficiency during pregnancy as a ferritin level below 30 ng/mL in any trimester. The World Health Organization uses a lower cutoff of 15 ng/mL during the first trimester.
My ferritin of 8 was below both thresholds.
But a ferritin result alone does not tell you whether you have iron-deficiency anemia. Anemia is diagnosed using hemoglobin and hematocrit, and the pregnancy thresholds change slightly by trimester. ACOG defines anemia as:
- Hemoglobin below 11 g/dL during the first trimester
- Hemoglobin below 10.5 g/dL during the second trimester
- Hemoglobin below 11 g/dL during the third trimester
Current recommendations for treating iron deficiency without anemia are not as settled as the recommendations for treating iron-deficiency anemia. I am also not sharing my complete laboratory panel here. My infusion was recommended based on more than one number.
Do not use someone else’s ferritin result, including mine, to diagnose yourself or determine your own supplement dose.
Why Do Iron Needs Increase During Pregnancy?
Iron helps the body make hemoglobin, which allows red blood cells to carry oxygen.
During pregnancy, blood volume expands and the body needs additional iron to support red blood cell production, the placenta and fetal development. Iron is also needed in preparation for blood loss during delivery.
The recommended dietary allowance increases from 18 milligrams per day for nonpregnant women ages 19 to 50 to 27 milligrams per day during pregnancy.
Reaching 27 milligrams from food alone can be difficult. According to the National Institutes of Health, most pregnant women in the United States consume less dietary iron than the estimated average requirement. Many prenatal vitamins contain iron, but the amount varies. Gummy prenatals frequently contain none.
Iron deficiency also becomes more common as pregnancy progresses. The body’s demand is increasing at the same time that nausea, food aversions, reflux or limited appetite may make it harder to eat iron-rich foods.
What Does Low Iron Feel Like During Pregnancy?
Iron-deficiency anemia can cause fatigue, weakness and difficulty concentrating. Some people also experience headaches, dizziness, shortness of breath, heart palpitations, feeling unusually cold, reduced exercise tolerance or pica, which is a craving for nonfood substances such as ice.
The frustrating part is that several of these symptoms can also occur during pregnancy without iron deficiency.
Of course you may feel more tired while pregnant. You are growing an entire human. But there is a difference between needing more rest and feeling like you can barely make it through the day.
For me, the intensity of the fatigue was the clue. Falling asleep around 7 p.m. had become normal, and I had very little energy left for anything beyond the basics.
Symptoms cannot diagnose low ferritin. They can, however, give you a reason to ask whether your symptoms deserve further evaluation.
Contact your prenatal care provider if you experience persistent or worsening fatigue, unusual weakness, shortness of breath, dizziness or a significant reduction in your ability to function. Seek urgent medical attention for chest pain, fainting, difficulty breathing at rest or a rapid heartbeat accompanied by other concerning symptoms.
Which Foods Contain Iron?
Food remains an important part of pregnancy iron intake, whether or not you also need a prenatal, separate iron supplement or infusion.
Dietary iron comes in two primary forms.
Heme iron is found in animal foods and is generally more readily absorbed. Sources include:
- Beef
- Turkey and chicken
- Salmon
- Sardines
- Canned light tuna
- Shrimp
- Other cooked seafood
Nonheme iron is found in plant foods and fortified foods. Sources include:
- Lentils
- White beans
- Kidney beans
- Chickpeas
- Tofu
- Fortified breakfast cereal
- Enriched breads and grains
- Potatoes
- Spinach
- Cashews
- Pumpkin seeds
A food does not have to contain an enormous amount of iron to contribute. Eating several iron-containing foods throughout the day adds up.
How Can You Improve Iron Absorption From Food?
Vitamin C can improve the absorption of nonheme iron from plant and fortified foods.
Useful combinations include:
- Iron-fortified cereal with strawberries
- Lentils with tomatoes or bell peppers
- Beans with salsa
- Tofu with broccoli
- Oatmeal with pumpkin seeds and kiwi
- Chickpeas with tomatoes and lemon
- A bean burrito with peppers and salsa
Meat, poultry and seafood can also improve the absorption of nonheme iron eaten in the same meal.
Calcium may interfere with iron absorption. If your clinician recommends a separate iron supplement, ask whether it should be taken at a different time from a calcium supplement, antacid or calcium-rich meal. There is no need to start micromanaging every food combination without guidance.
Can Food Fix Low Ferritin During Pregnancy?
Iron-rich foods can support daily intake and may help prevent deficiency. But once iron stores are significantly depleted, food may not provide enough iron quickly enough to correct the problem.
That was an important distinction in my own pregnancy. Eating spinach, steak or fortified cereal was not going to replenish my iron stores on the timeline my medical team wanted.
The appropriate treatment depends on whether someone has low ferritin alone, iron-deficiency anemia or another cause of abnormal blood counts. Gestational age, symptoms, tolerance of oral supplements and how quickly iron needs to be replenished may also affect the decision.
Some people may be advised to increase iron-rich foods. Others may need oral iron in addition to a prenatal. Some may be candidates for intravenous iron.
More iron is not automatically safer. Excess supplemental iron can cause side effects and may be harmful. Review the iron in your prenatal before adding another product, and do not choose a treatment dose based on a social media post.
Why Can Oral Iron Cause Constipation?
Oral iron is commonly used to treat iron-deficiency anemia during pregnancy and is generally considered the first-line option in the United States.
It can also be difficult to tolerate.
Depending on the product and dose, oral iron may cause nausea, abdominal discomfort, constipation or diarrhea. These side effects can make consistency difficult, especially if pregnancy has already slowed your digestion.
Different iron products contain different forms and amounts of elemental iron. The amount of elemental iron is listed on the Supplement Facts panel. A label that says “ferrous sulfate 325 mg,” for example, does not necessarily mean the product contains 325 mg of elemental iron.
Do not change the dose, schedule or form without speaking with your clinician. Ask what to do if the prescribed product is making you too constipated or nauseated to take consistently.
I cover food, fiber and hydration strategies more fully in my guide to pregnancy constipation.
You can also read more about why prenatal gummy formulations may contain little or no iron.
Why Did My Care Team Recommend an Iron Infusion?
An iron infusion delivers iron intravenously under medical supervision. It bypasses the digestive tract and can replenish a larger amount of iron than food or a typical prenatal provides.
IV iron is not a wellness drip or a casual energy treatment. It is medical care used for specific clinical situations.
In the United States, oral iron remains the standard first treatment for iron-deficiency anemia during pregnancy. IV iron may be considered when oral iron cannot be tolerated, does not produce an adequate response or when iron deficiency is severe later in pregnancy.
IV iron is typically administered during the second or third trimester because first-trimester safety data are limited. The particular formulation, dose and number of appointments depend on the patient and medical setting.
Newer evidence continues to examine when IV iron may be preferable. A large randomized trial presented by the Society for Maternal-Fetal Medicine in 2025 found that IV iron given during pregnancy was effective for moderate iron-deficiency anemia and reduced the need for additional IV iron or blood transfusion before delivery. These results do not make an infusion the right choice for every person with low ferritin.
For me, the decision followed lab work, significant symptoms and a conversation with my care team. I noticed my energy improve after the infusion, but that is my individual experience. It cannot predict how someone else will respond.
Questions to Ask About Your Iron Labs
You do not need to interpret an entire iron panel on your own. You can ask your prenatal care provider:
- Was my ferritin tested, or only my hemoglobin and hematocrit?
- What was my ferritin level?
- Does my complete blood count meet the criteria for anemia?
- Were my red blood cell indices or other iron studies abnormal?
- When should my labs be rechecked?
- How much iron is in my prenatal?
- Do I need additional iron based on my results?
- If you recommend oral iron, what dose and form should I take?
- What should I do if it causes constipation or nausea?
- Under what circumstances would you consider IV iron?
- Should my iron status be checked again after delivery?
Laboratory testing and treatment practices vary. Asking these questions can help you understand which results were evaluated and how your plan was chosen.
What I Wish I Had Known About Low Ferritin in Pregnancy
I wish I had not dismissed the severity of my fatigue simply because fatigue is common during pregnancy.
Common and insignificant are not synonyms.
I also wish more people knew that ferritin and hemoglobin answer different questions. A complete blood count is important, but it may not always show the earlier stage when iron stores are becoming depleted.
At the same time, ferritin should not be interpreted in isolation. A low result needs clinical context. A normal result can also be affected by inflammation. Treatment should account for the complete laboratory picture, symptoms and stage of pregnancy.
My ferritin dropping to 8 was not something I could solve with one “iron-rich” dinner. It was also not a reason for every pregnant person reading this to order a high-dose supplement or request an infusion.
It was a reason to pay attention, ask questions and work with my prenatal care team.
For realistic ways to include iron-rich foods alongside the rest of your nutritional needs, see my pregnancy grocery list.
If you want individualized help reviewing your prenatal, diet or pregnancy labs, learn more about my TTC and pregnancy nutrition counseling.
Are you a pregnancy, postpartum or women’s wellness brand looking for an RDN content creator or consultant? Learn more about partnering with Claire Rifkin Nutrition.
This article describes my personal experience and is provided for educational purposes. It is not a substitute for individualized medical care. Do not begin, stop or change an iron supplement based on this article. Speak with your prenatal care provider about your symptoms, laboratory results and treatment options.
