What Is Congenital Hypothyroidism in Children?

Medically Reviewed by Dan Brennan, MD on July 24, 2022

When a baby is born with an underactive thyroid, it’s called congenital hypothyroidism. With this condition, the thyroid gland doesn’t make enough thyroid hormones, which can cause health problems. If it’s detected and treated early, congenital hypothyroidism generally does not hinder proper growth and development. If left untreated, it can cause physical and developmental delays and irregular body functions. Some children need to take daily hormones for life, while others will outgrow the disorder.

What Is the Thyroid?

The thyroid is a small, butterfly-shaped gland at the front of your neck, right below your voice box. It plays a critical role in growth and development by contributing to cognitive and sexual development. It also helps the brain, heart, and other organs work as they should.

The thyroid gland produces thyroid hormones, which control metabolism. A normal metabolism helps make sure bodily functions like heart rate, energy level, growth, and body temperature remain at healthy levels.

An overactive thyroid (hyperthyroidism) produces too many hormones, while an underactive thyroid (hypothyroidism) doesn’t make enough. Both of these imbalances can lead to problematic symptoms.

What Are the Causes of Congenital Hypothyroidism?

Some of the most common causes of congenital hypothyroidism are:

  • Abnormal location of the gland (ectopic thyroid gland): If the thyroid gland is in an abnormal place in the neck, it won’t work as well as it should. 
  • Underdeveloped thyroid gland (thyroid hypoplasia): Sometimes, a child’s thyroid doesn’t form correctly during their mother’s pregnancy. When the baby is born, they may have a small or partially-developed thyroid. 
  • Missing thyroid gland (thyroid agenesis): In other cases, a child may be born without a thyroid gland.

Medical experts aren’t entirely sure what causes these problems, but sometimes it’s genetic.

Less commonly, a mother may take certain medications during pregnancy that may cause congenital hypothyroidism. Or, if the mother gets very high doses of iodine from her diet or a supplement, it can contribute to congenital hypothyroidism in a child at birth.

What Are Symptoms of Congenital Hypothyroidism?

Most babies don’t have any apparent symptoms of congenital hypothyroidism at birth. But since the thyroid plays such an important role in development, doctors screen all babies born in the U.S. to check their thyroid function.

Other children may display some of the following symptoms at birth or get them over the first few months of their life:

  • A belly button that sticks out too far (umbilical hernia)
  • A hoarse-sounding cry
  • A large soft spot on the top of the baby’s head
  • A large tongue
  • A puffy face
  • Constipation
  • Difficulty feeding
  • Dry skin
  • Muscle weakness
  • Poor appetite
  • Reduced energy levels
  • Slow bone growth
  • Yellow skin and eyes (jaundice)

The symptoms of congenital hypothyroidism can vary depending on the child, so screening is essential to catch the condition early on.

Which Children Are Most at Risk of Congenital Hypothyroidism?

Children with the following conditions may be at risk for getting congenital hypothyroidism:

Babies born prematurely and whose thyroid hasn’t completely developed yet may also be at risk of congenital hypothyroidism.

How Is Congenital Hypothyroidism Diagnosed?

All newborns are screened for thyroid problems right after birth. The test is completed with a few drops of blood taken from the baby’s heel and allows the doctor to identify the level of hormone production from the thyroid. If the doctor deems it necessary, they may also use a CT scan or ultrasound to get a better look at your child’s thyroid gland.

Children born prematurely may need to be re-tested for thyroid issues a few weeks after birth. Repeating the standard newborn screening tests will confirm whether their thyroid is developing as it should.

How Is Congenital Hypothyroidism Treated?

Most often, you can treat your child’s congenital hypothyroidism by giving them daily synthetic thyroid hormones. This kind of treatment is called thyroid hormone replacement therapy and will help restore their thyroid hormone levels. 

One such medication is called levothyroxine, which mimics the T4 (a type of thyroid hormone) your body produces. It’s available in tablet form, so, depending on your child’s age, you may need to crush up the tablet and mix it with a small amount of breastmilk, water, or non-soy baby formula.

Administering the medicine daily is critical to ensuring your child maintains steady blood levels. Your child’s doctor will monitor their blood thyroid hormone levels and adjust the medication as needed as they grow. Doctors typically recommend testing your child’s blood once monthly or bi-monthly up until they’re 6 months old. After that, blood tests usually occur every 2 to 3 months.

Can a Child Outgrow Congenital Hypothyroidism?

Many children with congenital hypothyroidism will need thyroid hormone replacement therapy for their entire life. This treatment will allow them to live a healthy life and participate in all kinds of activities without limitations. It will also help them grow and develop properly, especially during puberty.

On the other hand, some children outgrow congenital hypothyroidism and don’t need to continue treatment into adulthood. If your doctor thinks your child’s hypothyroidism may be temporary, they may recommend taking some time off the medication after your child turns three. At that point, the doctor can determine whether your child can stay off the medication or whether they should get back on it. 

What’s most important is that you work with your child’s doctor to create an ongoing treatment plan. Managing the condition closely will help avoid serious health problems and make sure that your child grows and develops properly.

Are There Any Possible Complications?

If left untreated, congenital hypothyroidism can cause the following complications:

  • Anemia (low red blood cell levels in the blood)
  • Low body temperature
  • Nervous system problems
  • Mental disabilities
  • Heart failure

Early detection and treatment are essential for children with congenital hypothyroidism and will provide the best quality of life possible.

What To Do if Your Child Is Diagnosed With Congenital Hypothyroidism

If your child has congenital hypothyroidism, it’s very important to administer any medication prescribed by your doctor. Make sure you attend all follow-up appointments and ask as many questions as you need to.

If you’re having trouble getting your child to take the medication, talk to your doctor about alternative methods to make sure they get the treatment they need.

Your child’s doctor will assess your child’s physical and mental development regularly to make sure the medication is working. They will also adjust the medication dosage based on their growth.

Remember that congenital hypothyroidism is a highly treatable condition and, with proper medical care, your child can live a happy and healthy life.

Show Sources


American Thyroid Association: “Congenital Hypothyroidism.”

Institute for Quality and Efficiency in Health Care: “How does the thyroid gland work?”

International Journal of Thyroidology: “Pediatric Quality of Life in Congenital Hypothyroidism: an Indonesian Study.”

Nemours KidsHealth: “Congenital Hypothyroidism.”

Stanford Children’s Health: “Congenital Hypothyroidism in Children.”

University of Rochester Medical Center: “Acquired Congenital Hypothyroidism in Children,” “Congenital Hypothyroidism in Children.”

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