Newborn screening tests show that your baby has congenital hypothyroidism. This means the thyroid doesn't make enough thyroid hormones. By giving your baby thyroid hormone medicine every day, you can help them grow and develop normally. Treatment is very important. Without it, a baby will have permanent changes to their growth and brain development. Most babies born with congenital hypothyroidism need to take thyroid hormone medicine for life.

• When giving your child thyroid medicine:
  • Give the exact dose that was prescribed every day. 
  • Crush the pill and mix it with a small amount of water, non-soy baby formula, or breast milk and give it to your baby with a medicine dropper. Be sure your child gets the whole dose of medicine.
  • Do not give the medicine with soy milk or soy formula, antacids, calcium or iron supplements, or "gas or colic drops" (simethicone) as these can make it hard for the body to absorb the medicine.
  • Give the medicine at the same time and mixed the same way every day. For example, a good routine could be that you give your baby the medicine mixed with breast milk right before a regularly scheduled 8 p.m. bedtime.
• Tell your health care provider before giving your baby any new medicines, vitamins, or dietary supplements.
• Be sure to take your child to all follow-up visits for exams, blood tests to check thyroid hormone levels, and medicine changes (if needed). Expect to see your health care provider every 2 weeks to every month for the first few years of your baby's life.

• Your baby has any new or worsening symptoms, such as not feeding well, constipation (hard, infrequent poops), a hoarse cry, jaundice that doesn't go away, dry skin, or swelling of the neck.
• You missed one or more doses of medicine.
• You have trouble making sure your child gets the thyroid medicine every day.

Your baby is difficult to awaken.

What do thyroid hormones do? The thyroid makes hormones that do many important things, such as helping with brain development, growth, pubertal development, and how the body uses energy.

What causes congenital hypothyroidism? The most common causes are:

• a baby's thyroid doesn't develop normally while in the womb
• a baby's thyroid doesn't respond to hormones normally 
• a baby is born without a thyroid 
• there is a problem with an area of the brain that controls thyroid hormone levels
• a mother takes certain medicines while pregnant