How does thyroid disease affect my supply?

Picture your body like a team that helps you feed your baby. Three important players are the thyroid, hypothalamus, and pituitary glands.

• First, your hypothalamus sends a message to your pituitary gland called thyroid-stimulating hormone (TSH).¹
• Next, TSH travels to your thyroid gland and tells it to make two special hormones: T3 and T4. These hormones help make milk for your baby.¹

There are two main things that can happen with these hormones: having too much (hyperthyroidism) or too little (hypothyroidism). Also, postpartum can cause the thyroid hormones to fluctuate between being too little and/or too much (postpartum thyroiditis). All of which can affect how much milk you can make for your baby.

Hyperthyroidism is when there is too much production of the thyroid hormone.²

• Symptoms: weight loss, nervousness, and sleep problems. 
• Diagnosis: High T3 and T4 levels are high and low TSH.
• Common type of hyperthyroidism: Graves Disease (autoimmune disorder); body’s immune system mistakes its healthy tissues as foreign and attacks them.
• Concerns for breastfeeding: lower levels of prolactin and oxytocin can affect milk production and milk “let down”.
• Other concerns: can cause osteoporosis, heart problems, and problems getting pregnant and maintaining pregnancy if not diagnosed and treated early.
• Treatment: Medications (and many are safe during lactation), radioactive iodine (not recommended during lactation), and/or thyroid removal.¹  

Hypothyroidism occurs when there is not enough production of the thyroid hormones.³

• Symptoms: fatigue, constipation, weight gain and depression. 
• Diagnosis: low  T3 and T4 levels and high TSH 
  • Deficiencies in magnesium, iodine, selenium, iron and potentially vitamin D have been linked with a poorly functioning thyroid. 
• Common type of hypothyroidism: Hashiomoto’s disease (autoimmune disorder)
• Concerns for breastfeeding:  can affect milk production and milk “let down”.
• Treatment: medications will normally be prescribed and many are safe during lactation. 
  • You may have to adjust the level of medication you were on during pregnancy to one that works well during lactation.¹ 

Postpartum Thyroiditis (PPTD) is an autoimmune disease that occurs in a small percentage of pregnancies.⁴  

• Diagnosis: often switches back and forth between hyperthyroidism and hypothyroidism which can make it difficult to diagnose.  

Follow Up:

What If I Have Questions?

If you are interested in learning more, these Aeroflow classes expand on some of the topics discussed above:

• Ultimate Breastfeeding Prep
• Lactation Q&A

Want More Info?

For a directory of Aeroflow’s other Care Guides offering information on pregnancy, baby care, and more, browse our comprehensive list of titles:

References