When the thyroid gland does not make enough thyroid hormone it is called hypothyroidism. Congenital hypothyroidism is when the disorder is present in a baby at birth. If not treated, it can lead to serious health problems. The thyroid is a gland. It’s located in the neck, just below the voice box. The thyroid gland makes thyroid hormone. This hormone helps control the metabolism. This is the rate at which every part of the body functions. Thyroid hormone keeps the metabolism at a healthy pace. This helps the brain, heart, muscles, and other organs work well. A normal metabolism also helps ensure a healthy temperature, heart rate, energy level, and growth rate. If a baby does not make enough thyroid hormone, it can cause serious problems such as mental disability, growth delays, or loss of hearing.


The most common cause of congenital hypothyroidism is an autoimmune reaction. This is when the body’s immune system slowly destroys the thyroid gland. It can be caused by antibodies in your body before your baby's birth. Or it can be caused by treatment of a thyroid problem while you are pregnant.

Risk Factors

A child is at risk for congenital hypothyroidism if he or she has any of these:

  • A chromosomal disorder such as Down syndrome, Williams syndrome, or Turner syndrome
  • An autoimmune disorder such as type 1 diabetes or celiac disease
  • Injury to the thyroid gland


A newborn baby may have no symptoms at first. Symptoms can include:

  • Yellowing of the skin and eyes (jaundice)
  • A hoarse-sounding cry
  • Low appetite
  • Bellybutton that sticks out too far (umbilical hernia)
  • Constipation
  • Slow bone growth
  • Weak muscles
  • Lack of energy
  • A puffy face
  • A large tongue

Symptoms can vary with each child.


By law, all newborns are screened in the first few days of life for serious diseases. The testing is done with a few drops of blood taken from the baby’s heel. One of the tests is for thyroid function. The blood is tested for amounts of hormones from the thyroid. It is also tested for amounts of hormones that tell the thyroid to make more hormones. Your baby’s healthcare provider may also advise an imaging test of the thyroid gland.


Congenital hypothyroidism is most often treated by giving a child synthetic thyroid hormones every day. Your child will likely need to take these for life. In some cases, the thyroid gland may start working again. This may happen by age 3. The thyroid gland will be tested over time with blood tests. This can show if the thyroid starts working on its own. Your child’s growth and development will also be tracked over time.                                                            


Congenital hypothyroidism can affect a child's normal growth and development. This includes sexual development. If untreated, the condition can also lead to:

  • Low red blood cell levels in the blood (anemia)
  • Low body temperature
  • Heart failure

Living with

Congenital hypothyroidism can affect a child's normal growth and development. It’s important for a child to continue treatment until after puberty. This will help make sure a child reaches his or her normal adult height. Some children do not need to continue treatment into adulthood. Work with your child's healthcare providers to create an ongoing plan to manage your child’s condition.

When to Call a Healthcare Provider

Call your child's healthcare provider if you’re concerned about your child's growth, or if he or she has any signs of congenital hypothyroidism.

Key Points

  • Congenital hypothyroidism is when the thyroid gland doesn't make enough thyroid hormone. It’s the most common thyroid disorder in children.
  • Not enough thyroid hormone leads to signs such as slow growth, lack of activity, and poor performance in school.
  • The most common cause is an autoimmune reaction that destroys the thyroid gland.
  • Treatment may include taking thyroid hormones to increase the level of hormones in the body. Some children will need to take hormones for life. Other children may outgrow the disorder.
  • Congenital hypothyroidism can impair a child's normal growth and development. It’s important for a child to continue treatment until after puberty. This will help ensure a child reaches his or her normal adult height.

Next Steps

Tips to help you get the most from a visit to your child’s healthcare provider:

  • Know the reason for the visit and what you want to happen.
  • Before your visit, write down questions you want answered.
  • At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you for your child.
  • Know why a new medicine or treatment is prescribed and how it will help your child. Also know what the side effects are.
  • Ask if your child’s condition can be treated in other ways.
  • Know why a test or procedure is recommended and what the results could mean.
  • Know what to expect if your child does not take the medicine or have the test or procedure.
  • If your child has a follow-up appointment, write down the date, time, and purpose for that visit.
  • Know how you can contact your child’s provider after office hours. This is important if your child becomes ill and you have questions or need advice.