Congenital Hypothyroidism

Congenital hypothyroidism (hy-poh-thy-roi-diz-uhm) is a condition found in newborns. Congenital means that they are born with this condition. All babies are tested for this condition within the first week of life.  

When a baby has this condition, the thyroid gland is not making enough hormones for the brain and body to grow and develop. 

Congenital hypothyroidism can easily be treated with a daily medicine.  Children who do not take medicine to treat hypothyroidism will have trouble with growing and developing. Most children take this medication for life. 

The thyroid gland is found in the neck and is shaped like a butterfly.  The thyroid gland makes thyroid hormones that are important for growth and development.  These hormones are also important for energy and for the heart, liver, kidneys and skin.  

The brain makes a hormone called thyroid-stimulating hormone (TSH). There is a gland in the brain called the pituitary gland that talks to the thyroid gland.  When a child’s TSH is too high, the pituitary gland works hard to tell the thyroid to make more thyroid hormone.  The thyroid gland cannot respond to the signal from the brain so babies with congenital hypothyroidism who are not on medicine will have a high TSH.

One in 4,000 babies is diagnosed with this condition. There are many causes of congenital hypothyroidism.

  • A baby can be born without a thyroid gland.
  • The thyroid gland may be in the wrong place.
  • The thyroid gland may not work correctly.

Your child's healthcare provider will talk with you about the cause of your baby’s hypothyroidism.

Congenital hypothyroidism can have little or no symptoms.  Babies who have symptoms may spend less time awake, eat poorly, may have floppy arms and legs, and low energy.  Some babies have constipation, yellowing of the skin, and low temperature.

This condition can be easily treated by taking a medicine every day. This medicine is called levothyroxine and it replaces the thyroid hormone that your child's thyroid gland is unable to make.  It is very important to make sure your child gets this medicine every day. 

Sometimes the medicine dose will need to be changed.  Never change the medicine dose on your own.  Your child’s healthcare provider will let you know when changes need to be made.  

Give this medicine with small amounts of formula or food.  You may break the tablets in half or crush them to make it easier for your child to take.  If your baby needs to be on soy formula or is on iron, notify your healthcare provider.  Soy and iron may interfere with how the medicine works.

There are things to watch for that can help your healthcare provider find the right dose of medicine to give your child.

The dose may be too high if your child has:

  • Trouble sleeping
  • Shaking (tremors)
  • Weight loss
  • Irritability, fussiness
  • Diarrhea
  • Excessive hunger 

The dose may be too low if your child has:

  • Been sleeping too much
  • Constipation
  • Cold, dry skin
  • Gained weight too quickly
  • Low energy / activity level 

Call your child's healthcare provider if any of the above symptoms develop.  Your healthcare provider may do a blood test to check thyroid levels.  


Last Updated 09/2013