Congenital Hypothyroidism

Hypothyroidism is the condition in which the thyroid gland does not make enough thyroid hormone. Congenital hypothyroidism is when the disorder is present in a baby at birth. If not treated, it can lead to serious health problems.

What does the thyroid do?

The thyroid is a gland located in the neck, just below the voicebox. The thyroid gland makes thyroid hormone. This hormone helps control the metabolism. Metabolism 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. Normal metabolism supports a healthy temperature, heart rate, energy level, and growth rate. If a baby does not make enough thyroid hormone, serious problems may develop such as mental disability, growth delays, or loss of hearing.  

Causes of congenital hypothyroidism

The most common cause of congenital hypothyroidism is the failure of the thyroid to form normally before birth. Less commonly, congenital hypothyroidism can be caused by treatment of the mother for a thyroid problem prior to or during pregnancy.

Symptoms of congenital hypothyroidism

A newborn usually does not have symptoms at first. Symptoms can vary with each child.

Symptoms in newborns can include:

  • Yellowing of the skin and eyes (jaundice)

  • A hoarse-sounding cry

  • Trouble feeding

  • Bellybutton that sticks out too far (umbilical hernia)

  • Constipation

  • Weak muscles

  • Lack of energy

  • A large tongue

  • Dry or cold skin

Diagnosing congenital hypothyroidism

By law in the United States and many other countries, all newborns are screened in the first few days of life for serious diseases. The tests are done on  a few drops of blood taken from the baby’s heel. One tests is for thyroid function. The blood is tested to measure amounts of thyroid-related hormones. It is also tested for amounts of hormones that tell the thyroid to make more hormones. Your baby’s health care provider may also advise an imaging test of the thyroid gland.

Treating congenital hypothyroidism

Congenital hypothyroidism is treated by giving your child synthetic thyroid hormones (called levothyroxine) every day. Your child will likely need to take this hormone for life. In a few cases, the thyroid gland may start working again 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. Never stop taking thyroid hormone unless instructed to do so by your health care provider.