Why So Many Pregnant Women Are Running on Empty

Written By The Wellness Lounge

Walk into almost any obstetric practice today and you'll find pregnant women with ferritin levels of 7, 8, or 9 ng/mL.

Unfortunately, many have been told this is simply part of pregnancy.

It isn't.

While iron deficiency is common during pregnancy, a ferritin of 7–8 represents severely depleted iron stores. In many cases, the deficiency did not begin during pregnancy. Pregnancy simply exposed a problem that had been developing for years.

First, What Is Ferritin?

Ferritin is your body's iron storage protein.

Think of ferritin as your iron savings account. It represents the iron reserve your body can draw upon when demands increase. Iron is essential because it allows your body to make hemoglobin, the protein in red blood cells that carries oxygen from your lungs to every tissue, organ, and cell in your body.

During pregnancy, the demands for iron increase dramatically.

A woman can have a normal hemoglobin level while her ferritin is critically low. This is one reason iron deficiency often goes unnoticed until symptoms become severe.

The Real Problem: Many Women Start Pregnancy Already Iron Deficient

One of the biggest misconceptions is that pregnancy causes iron deficiency. In reality, many women enter pregnancy with inadequate iron stores. Common reasons include:

  • Heavy menstrual bleeding

  • Fibroids

  • Adenomyosis

  • Endometriosis

  • Multiple pregnancies

  • Blood donation

  • Restrictive dieting

  • Endurance exercise

  • Previous iron deficiency that was never fully corrected

A woman may spend years gradually draining her iron reserves while maintaining a "normal" hemoglobin level.

Then she becomes pregnant.

Suddenly the body's iron requirements skyrocket.

The result is often a ferritin level in the single digits by the second or third trimester.

Pregnancy Requires an Enormous Amount of Iron

Pregnancy places one of the greatest iron demands on the human body. The average pregnancy requires approximately 1,000 mg of additional iron to support:

  • Expansion of maternal blood volume

  • Increased red blood cell production

  • Placental development

  • Fetal growth

  • Blood loss during delivery

Researchers estimate total pregnancy iron requirements at approximately 1,000 mg, with significant iron needed for maternal blood production, placental development, fetal growth, and delivery-related blood loss.

If a woman begins pregnancy with ferritin levels already in the teens or twenties, these increased demands can quickly deplete her remaining reserves.

Your Blood Volume Expands Faster Than Your Iron Stores

Pregnancy causes dramatic physiologic changes. Maternal plasma volume increases approximately 40–50%, while red blood cell mass increases approximately 20–30%. This expansion begins early in pregnancy and continues throughout gestation. Essentially, the body is trying to manufacture a much larger blood supply.

That process requires iron.

Without adequate iron reserves, ferritin levels continue to fall as pregnancy progresses.

Prenatal Vitamins Are Often Not Enough

Most prenatal vitamins contain approximately 27–30 mg of elemental iron.

This amount is designed to help meet the needs of pregnancy, but it is often insufficient to rebuild depleted iron stores. Pregnant women require substantially more iron than nonpregnant women, and iron demands rise significantly as pregnancy advances.

For a woman who enters pregnancy already iron deficient, a prenatal vitamin may slow the decline but may not be enough to restore adequate reserves.

Many Providers Are Looking at Hemoglobin Instead of Ferritin

Routine prenatal screening commonly focuses on:

  • Hemoglobin

  • Hematocrit

Ferritin is not always measured unless anemia develops. This creates a major blind spot.

A woman may have:

  • Hemoglobin: 12 g/dL

  • Ferritin: 7 ng/mL

Yet still experience:

  • Fatigue

  • Exercise intolerance

  • Shortness of breath

  • Heart palpitations

  • Restless legs

  • Hair loss

  • Poor recovery from exercise

Iron deficiency occurs long before anemia develops. Research shows that many pregnant women with iron deficiency do not yet meet criteria for anemia. One recent study found that most first-trimester women with iron deficiency were not anemic.

What Ferritin Level Is Considered Iron Deficient?

This is where things become interesting.

The World Health Organization defines iron deficiency during pregnancy at ferritin levels below 15 ng/mL. However, the American College of Obstetricians and Gynecologists uses a ferritin threshold below 30 ng/mL because it identifies substantially more women with iron deficiency.

Several recent publications suggest that physiologic iron deficiency during pregnancy may begin even before ferritin reaches 15 ng/mL and that thresholds closer to 20–30 ng/mL may better identify women at risk.

In other words:

A ferritin of 7–8 is not borderline.

It is profoundly depleted.

Why We May Be Seeing More Cases Than Ever

Many clinicians report seeing increasing numbers of women with very low ferritin levels. Several factors may contribute:

  • Heavy menstrual bleeding

  • Delayed childbearing

  • Multiple pregnancies

  • Chronic inflammation

  • Fibroids and adenomyosis

  • Dietary patterns that provide inadequate iron

There has also been growing discussion regarding menstrual changes following COVID-19 infection and vaccination. While temporary menstrual changes have been documented, there is currently insufficient evidence to conclude that these changes are a primary driver of widespread iron deficiency years later.

What remains clear is that chronic heavy menstrual bleeding continues to be one of the leading causes of iron depletion in women of reproductive age.

Why This Matters

Iron deficiency during pregnancy is not just about feeling tired. Maternal iron deficiency and anemia have been associated with:

  • Reduced exercise tolerance

  • Severe fatigue

  • Increased risk of postpartum anemia

  • Increased need for transfusion

  • Preterm birth

  • Low birth weight

  • Potential effects on infant neurodevelopment

Professional organizations continue to emphasize the importance of identifying and treating iron deficiency during pregnancy because of these maternal and fetal risks.

Why Iron Status Matters During Labor and Delivery

Labor and delivery are physically demanding events that place significant stress on the body. Every woman loses blood during childbirth, whether she delivers vaginally or by cesarean section. If a mother enters labor with severely depleted iron stores, she has less reserve available to tolerate that blood loss.

Think of ferritin as your body's emergency backup supply of iron. When ferritin is already in the single digits, there is very little reserve available if bleeding occurs during delivery.

Women who enter labor with iron deficiency are more likely to:

  • Develop postpartum anemia

  • Experience severe fatigue after delivery

  • Have delayed recovery

  • Struggle with physical stamina while caring for a newborn

  • Experience dizziness, weakness, or shortness of breath postpartum

  • Require iron infusions or, in severe cases, blood transfusions

Iron is also critical for energy production and muscle function. While labor is influenced by many factors, iron deficiency can leave a mother starting one of the most physically demanding events of her life with a reduced capacity to deliver oxygen to her muscles and tissues.

The goal is not simply to avoid anemia on a lab report. The goal is to help women enter labor with adequate iron reserves so they have the physiological resources needed for delivery, recovery, breastfeeding, and the demands of early motherhood.

If pregnancy is a marathon, labor and delivery are the finish line. No one would intentionally start a marathon with an empty fuel tank, yet many women are entering labor with ferritin levels in the single digits and virtually no iron reserves left to draw from.

Ways to Support Healthy Iron Levels at Home

1. Increase Heme Iron Intake

Heme iron is the most absorbable form of iron and is found in animal foods.

Focus on:

  • Beef

  • Bison

  • Lamb

  • Venison

  • Elk

  • Liver (if tolerated and appropriate)

  • Dark meat poultry

  • Sardines

A 4–6 oz serving of red meat several times per week can provide significantly more absorbable iron than many plant sources.

2. Pair Iron-Rich Foods with Vitamin C

Vitamin C can significantly increase iron absorption.

Good combinations include:

  • Steak + roasted bell peppers

  • Ground beef tacos + fresh salsa

  • Iron supplement + orange juice

  • Blackstrap molasses + orange juice

  • Spinach salad + strawberries

  • Lentils + lemon juice

Vitamin C-rich foods:

  • Oranges

  • Strawberries

  • Kiwi

  • Bell peppers

  • Citrus fruits

  • Broccoli

3. Blackstrap Molasses

Blackstrap molasses contains naturally occurring iron and trace minerals.

Many people use:

  • 1 tablespoon daily

  • Mixed into warm water

  • Mixed into tea

  • Added to smoothies

A common traditional remedy is:

  • 1 tablespoon blackstrap molasses

  • 4–8 oz orange juice

While it won't correct severe iron deficiency by itself, it can be a helpful addition to a broader plan.

4. Cook in Cast Iron Cookware

Research has shown that cooking acidic foods in cast iron cookware can increase the iron content of food.

Examples:

  • Chili

  • Tomato sauces

  • Soups

  • Stews

The increase isn't dramatic, but over months it can contribute additional dietary iron.

5. Increase Iron-Rich Foods Beyond Red Meat

Additional sources include:

  • Oysters

  • Clams

  • Mussels

  • Sardines

  • Eggs

  • Turkey thighs

  • Chicken thighs

Plant sources:

  • Lentils

  • Beans

  • Chickpeas

  • Pumpkin seeds

  • Tofu

  • Quinoa

Keep in mind that plant-based iron is absorbed less efficiently.

6. Avoid Iron Blockers Around Meals

Certain foods and beverages can reduce iron absorption.

Try separating these by 1–2 hours from iron-rich meals or supplements:

  • Coffee

  • Tea

  • Calcium supplements

  • Large amounts of dairy

  • Antacids

Many patients unknowingly take an iron supplement with coffee and significantly reduce absorption.

7. Consider an Oral Iron Supplement

Common options include:

  • Iron bisglycinate (often better tolerated)

  • Ferrous sulfate

  • Ferrous fumarate

  • Ferrous gluconate

Supplement with cofactors:

  • Lactoferrin

  • Vitamin C

Some patients absorb iron better taking it:

  • Every other day

  • With vitamin C

  • Away from coffee, tea, and calcium

The Bigger Question We Should Be Asking

Instead of asking:

"Why did this pregnant woman develop a ferritin of 7?"

We should be asking:

"What was her ferritin before she became pregnant?"

In many cases, pregnancy is not the cause of the deficiency. It is simply the event that finally reveals it.

A ferritin of 7–8 during pregnancy often represents years of gradual iron depletion from heavy menstrual bleeding, inadequate replacement, or previously unrecognized iron deficiency.

By the time ferritin reaches single digits, the problem has usually been developing long before conception.

Key Takeaway

Pregnancy does not create iron deficiency out of nowhere.

More often, it exposes iron deficiency that has been quietly progressing for years.

If we want healthier pregnancies, healthier mothers, and healthier babies, we need to stop waiting for hemoglobin to fall and start paying attention to ferritin before pregnancy begins.

References

The Wellness Lounge
Previous

Iron Deficiency: When "Normal" Isn't Good Enough
Next

“Your Labs Are Normal”