Low Milk Supply: Causes, Signs, and Breastfeeding Help

Worried about low milk supply during pregnancy or after your baby is born? You are not alone. As an IBCLC (International Board Certified Lactation Consultant) candidate (taking my exam in April), I work with new and expectant parents every day who are seeking clear, evidence-based breastfeeding help, especially when feeding feels harder than expected.

Low milk supply is rarely caused by one single issue. It is often influenced by breast anatomy, hormones, medical history, and early feeding experiences. Understanding the why behind low milk supply allows us to create a feeding plan that supports both your baby’s growth and your well-being.

How an IBCLC Identifies Insufficient Glandular Tissue (IGT)

One possible cause of primary low milk supply is Insufficient Glandular Tissue (IGT), sometimes called breast hypoplasia. IGT means there is less milk-producing tissue available in the breasts.

Signs an IBCLC looks for include:

Breast Changes During Pregnancy

• Little or no breast growth

• No increased sensitivity, warmth, or fullness

• Your breasts did not feel heavier or swollen in early pregnancy

Breast Changes In Puberty

• Did your breasts change during puberty? Early breast development can affect later milk-making capacity.

Breast Changes After Birth

• Minimal or uneven engorgement

• Fullness in some areas of the breast but not others

• Glandular tissue often missing in the lower center quadrant

Breast Shape Patterns

• Widely spaced breasts

• Nipples that point outward or downward

• Noticeable breast asymmetry

These signs do not automatically mean you cannot breastfeed, but they are important clues when evaluating persistent low milk supply with an IBCLC.

Primary Causes of Low Milk Supply (Medical & Hormonal)

Primary low milk supply often originates from factors present before or during pregnancy.

Common Risk Factors

• Age 30–40+

• BMI greater than 27

• History of breast or chest surgery

• Hypoplasia / IGT

• Spinal cord or nerve injury

  • Including scoliosis or car accidents

• The 4th intercostal nerve (in the space just below your 4th rib, along your chest wall) plays a critical role in milk production signaling

Pregnancy & Birth Complications

• Placental insufficiency

• Preterm birth

• Retained placental fragments

• Hypertension or HELLP syndrome

Medical Conditions Linked to Low Milk Supply

• Type 1 or Type 2 diabetes

• PCOS (this may affect supply), about 1/3 of parents with PCOS had a lower supply

• Thyroid dysfunction (hypo- or hyperthyroid)

• Hypopituitarism

• Hyperandrogenism

• History of infertility

Secondary Causes of Low Milk Supply (Feeding & Environmental Factors)

Secondary low milk supply develops after birth and is often related to feeding management rather than anatomy.

Lactation-Related Contributors

• Delayed breastfeeding initiation

• Non-breastfeeding-supportive hospital practices

• Misunderstanding how supply and demand works

• Ineffective pumping routines

• Improper or prolonged nipple shield use

• Poor latch or positioning

• Early or frequent supplementation without supply protection

Lifestyle & Hormonal Factors

• Certain medications (ex: bromocriptine, ergotamine, cabergoline, decongestants like Pseudoephedrine, dopaminergic drugs, anticholinergics, diuretics, terbutaline, betamethasone)

• Smoking

• Nutritional deficiencies (iron, zinc, protein)

• Calorie intake consistently below ~1500/day

• New pregnancy

• Estrogen-containing birth control

• Return of menstruation
  

Many of these factors are modifiable with timely breastfeeding help from an IBCLC.

How an IBCLC Manages Low Milk Supply

When families come to me for breastfeeding help, my goals are always:

1. Feed the baby

2. Protect milk supply

3. Identify the root cause of low milk supply
   

What an IBCLC Assesses

• Latch and positioning

• Milk transfer at the breast

• Diaper output and weight trends

• Pump type, fit, and effectiveness

• Whether supplementation is needed, and how to do it strategically
  

Nipple shields should be used only when clinically indicated and with close follow-up from an IBCLC.

Supplementation Options When Needed

Supplementation does not mean breastfeeding has failed. When required, options include:

1. Expressed breast milk

2. Pasteurized human donor milk

3. Infant formula
   

For many families, supplementation is a temporary bridge that supports baby while protecting long-term breastfeeding goals.

Get Personalized Breastfeeding Help From an IBCLC

Low milk supply is complex and you deserve individualized care, not one-size-fits-all advice. Whether you’re pregnant and planning ahead or postpartum and feeling unsure about feeding, working with an IBCLC early can make a significant difference.

Professional breastfeeding help can:

• Identify causes of low milk supply

• Create realistic, sustainable feeding plans

• Reduce stress and confusion

• Support both baby growth and parent mental health
  
  

If you’re concerned about low milk supply or want proactive breastfeeding help, schedule a lactation consultation with an IBCLC for prenatal or postpartum support.

Written by Kathleen Stern (bio here). For more infant feeding and parent support, reach out to Kathleen at www.strongnestconsulting.com

Last updated December 19, 2025