Iron, Thyroid & Postpartum Fatigue: “Normal” vs Optimal
So many pregnant and postpartum people are told that exhaustion, anxiety, low mood, brain fog, or low milk supply are just part of having a baby. That this season is supposed to feel hard. That you should expect to be depleted. That this is simply the cost of motherhood.
But what if some of what we’re calling “normal” isn’t actually ideal?
In a recent episode of the Be Well Baby Podcast, I sat down with Dr. Stephanie Hayes, a naturopathic physician and acupuncturist here in Portland, Oregon, to talk about two of the most commonly overlooked — and under-treated — contributors to postpartum struggle: iron deficiency and thyroid dysfunction.
This conversation has the potential to completely change how you understand your body, your symptoms, and what kind of care you deserve.
Let’s Start With Fatigue
Fatigue is one of the most common complaints I hear from pregnant and postpartum clients. And yes — caring for a baby is tiring. Sleep is disrupted. Your nervous system is learning something entirely new.
But there’s a difference between situational tired and physiologic depletion.
According to Dr. Hayes, one of the biggest contributors to deep, persistent fatigue — especially in people with uteruses — is iron deficiency.
And here’s where things often go wrong.
Iron Deficiency Is Not the Same as Anemia
Most providers screen for iron deficiency anemia, which shows up on a standard CBC (complete blood count). But iron deficiency can exist long before anemia develops.
Think of iron stores like a pantry.
Ferritin tells us how stocked the pantry is
Hemoglobin tells us whether you’re still managing to cook meals
Many bodies — especially pregnant bodies — will keep making “good enough” red blood cells even when iron stores are dangerously low. You can have a normal CBC and still be profoundly iron deficient.
Why Ferritin Matters
Most people become symptomatic when ferritin drops below 30–50
An ideal ferritin is closer to 100
Many pregnant and postpartum people are walking around with ferritin in the teens — or single digits — without anyone noticing
Iron is rapidly depleted by:
Menstruation
Pregnancy (blood volume doubles early on)
Birth blood loss
Lactation
If you entered pregnancy with a half-empty pantry, your body will prioritize baby — pulling iron from muscles, organs, bones, and the nervous system — to get through.
You may survive it.
But you won’t necessarily feel good.
Iron’s Role Goes Far Beyond Energy
Iron isn’t just about red blood cells.
It’s essential for:
Thyroid hormone production
Milk production (milk is made from blood)
Nervous system health
Myelin production (the protective coating around nerves)
Low ferritin can contribute to:
Chronic fatigue
Low mood or irritability
Anxiety
Low milk supply
Numbness, tingling, carpal tunnel, and nerve pain
A Real Clinical Example
I recently worked with a postpartum client who had been diagnosed with carpal tunnel after nerve conduction testing. She also had tingling in her feet and worsening nerve pain from an old injury.
No one had connected the dots.
Her ferritin level?
18.
Iron is required for proper nerve signal transmission. When iron stores are depleted, nerves literally cannot conduct signals the way they should. Her symptoms weren’t random — they were physiologic.
Iron and the Thyroid: An Overlooked Connection
Iron is a required ingredient for thyroid hormone production.
If your iron “pantry” is empty, your thyroid cannot do its job effectively — even if your thyroid labs appear normal at first glance.
Low iron can:
Worsen existing thyroid dysfunction
Contribute to postpartum thyroiditis
Affect prolactin levels and milk supply
This is one reason thyroid issues are so often missed or mismanaged postpartum.
Understanding the Thyroid (In Plain Language)
Your thyroid is essentially your metabolic furnace.
It influences:
Energy
Metabolism
Mood
Digestion
Ovulation and fertility
Temperature regulation
When the furnace is turned too high (hyperthyroidism / Graves’):
Anxiety
Insomnia
Feeling hot
Racing thoughts
Buzzing or vibrating sensations in the body
When the furnace is turned too low (hypothyroidism / Hashimoto’s):
Exhaustion you cannot push through
Depression
Cold intolerance
Constipation
Brain fog
Postpartum Thyroiditis: Common, Missed, and Dismissed
Postpartum thyroiditis is an inflammatory thyroid condition that often has an autoimmune component.
What’s wild?
It’s rarely taught
It’s rarely screened for
Symptoms are often dismissed as “just postpartum”
It often follows a pattern:
A hyperthyroid phase (anxiety, insomnia, buzzing)
Followed by a hypothyroid crash (deep fatigue, low mood)
It can show up:
Weeks postpartum
Months postpartum
Even up to a year or more after birth
Red Flags to Pay Attention To
These are symptoms worth investigating — not dismissing:
Possible hyperthyroid signs:
Anxiety that won’t settle
Inability to sleep despite sleep opportunity
Internal buzzing or vibrating sensations
Possible hypothyroid signs:
Fatigue that feels flu-like or crushing
Low mood that doesn’t lift
Feeling slowed down in every system
Labs Worth Asking For
If something feels off, these labs matter:
Ferritin
CBC
TSH
Free T3
Free T4
Thyroid peroxidase (TPO) antibodies
Thyroglobulin antibodies
A “normal” TSH alone is not enough.
Treatment That Actually Helps
Oral Iron
Can help if absorption is good
Better tolerated forms include iron bisglycinate
Can take months to raise ferritin
Iron Infusions
Often life-changing postpartum
Covered by insurance in many cases for iron deficiency (not just anemia)
Much faster and more reliable
Ferritin may temporarily rise very high — this is expected
If ferritin is below 30 and you’re pregnant, postpartum, menstruating, or lactating, it is extremely hard to replete iron through food and supplements alone.
Long-Term Effects of Untreated Depletion
Unaddressed iron deficiency can contribute to:
Chronic fatigue
Heavy or flooding periods
Poor clotting
Perimenopausal bleeding issues later on
Unaddressed thyroid dysfunction can increase risk for:
Postpartum mood disorders
Fertility challenges
Recurrent postpartum thyroiditis in future pregnancies
The good news?
These are treatable.
This Is Not Your Fault
None of this is a personal failure.
It’s a systems problem.
Women’s bodies are under-researched. Symptoms are minimized. Postpartum care is fragmented. Many providers are focused on safety — not optimization.
You are not weak.
You are not dramatic.
You are responding appropriately to physiologic depletion.
Trust Your Body
You have lived in your body a long time.
If something feels off — if the fatigue feels extreme, the anxiety feels different, the sadness feels heavier — you deserve to be taken seriously.
Ask for labs. Bring support to appointments. Seek second opinions.
Feeling functional is not the same as feeling well.
You deserve better than “this is normal.”
You deserve optimal.
If this post resonated, share it with someone who’s pregnant, postpartum, or quietly struggling. No one should have to navigate this alone.
