The Most Important Thing to Know About Milk Supply From a NICU RN, IBCLC, and mom of 3 who breastfed until age 4

Hey Mama,

Let’s get straight to it: milk supply runs on one basic principle — supply and demand. The more milk that’s removed (by baby or pump), the more milk your body makes. Sounds simple, right? But here’s the kicker: simple doesn’t always mean easy.

As a NICU nurse, IBCLC, and mama who nursed three kids until age four, I can tell you — understanding milk supply isn’t just about biology. It’s about emotions, preparation, skill, gear, and trust in your body. Here’s what I wish every pregnant mom knew before the first latch.

1. The Emotional Side of Supply

Stress, worry, and self-doubt? They can mess with your let-down reflex faster than you can say “is my baby getting enough?” Milk supply isn’t just physical — it’s emotional. Confidence, calm, and connection fuel oxytocin, which fuels milk flow.

👉 Translation: Taking care of you helps take care of your milk.

2. Education = Empowerment

Milk supply thrives when you understand the basics:

• Newborn stomach sizes are tiny (so don’t panic over drops).

• Cluster feeding is normal (not a sign of low supply).

• Frequent removal = more milk (not “spoiling” your baby).

Learning this before birth means fewer 2 a.m. Google spirals. Bonus points if you schedule a prenatal visit with an IBCLC — prevention is always easier than fixing supply issues later.

3. Breastfeeding Is a Skill (Not Magic)

Latch, positioning, and milk transfer are learned skills — for both you and baby. It’s normal to need practice and support. A painful latch or slow gain doesn’t mean your body is broken. It means you need tweaks, not defeat.

4. Gear & Equipment — Keep It Simple

You don’t need a closet full of gadgets to protect your supply. What matters:

• A well-fitting pump if you’ll be separated from baby

• Comfort-focused nursing bras

• Support from people who get it

Everything else? Nice-to-have, not need-to-have. (Looking at you, overpriced gadgets.)

5. Evidence + Instinct = Gold Standard

Research shows that frequent milk removal is the #1 factor in building and protecting supply. But let’s not forget — women have breastfed for thousands of years with instinct, rhythm, and generational knowledge. Trust the evidence, but also trust your gut.

6. When Biology Gets in the Way

Here’s the truth: while the vast majority of mothers can make enough milk, some do face real medical hurdles — and knowing that can help you seek support early.

• Insufficient Glandular Tissue (IGT): Occurs in about 1–5% of women. Breast tissue simply didn’t fully develop during puberty, pregnancy, or both.

• Polycystic Ovary Syndrome (PCOS): Affects up to 10% of women and can impact milk supply due to hormonal imbalances.

• Thyroid Disorders: Both hypo- and hyperthyroidism can interfere with lactation hormones. Around 5–10% of postpartum women experience thyroid dysfunction.

• Diabetes (Type 1, Type 2, or Gestational): Can delay the onset of mature milk ("milk coming in") and affect supply regulation.

• Genetic Factors: Rare genetic conditions affecting hormone receptors or metabolism may impact supply — though these are uncommon.

If you’re in that small percentage, it’s not your fault. It’s not about willpower, diet, or “trying harder.” It’s about biology. And with the right plan (sometimes combining breastfeeding, pumping, and supplementation), you and your baby can still thrive.

7. Health Benefits of a Strong Supply

When supply is well-supported, your baby gets all the antibodies, live immune cells, and perfect nutrition your body custom-makes daily. And for you? Lower risk of breast and ovarian cancers, faster postpartum healing, and long-term protection for heart and metabolic health.

Breastfeeding isn’t just feeding — it’s health care for two.

Final Thought

The most important thing to know about milk supply? It’s not about hacks, teas, or magic foods. It’s about frequent milk removal, confidence, and support.

And if biology throws you a curveball? That doesn’t erase your effort, your love, or your success as a mother.

Protect your mental health, prepare with good education, lean on your IBCLC, and remember — milk supply is not a test. It’s a relationship.

Welcome to the Milk Drunk Club, Mama. You belong here.