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Congenital Hyperthyroidism In Babies: An Inside Look

The Asian Parent logo The Asian Parent 4/7/2022 Pheona Ilagan
© Provided by The Asian Parent

One in every five thousand newborns has congenital hyperthyroidism. This condition is more common in female babies than males for unknown reasons. Twice as many females are diagnosed with this condition at birth compared to males.  

If your child is suffering from congenital hyperthyroidism, talk to your doctor. Early treatment can help prevent serious problems, like heart problems and bone damage.

What Is Congenital Hyperthyroidism?

Congenital hyperthyroidism occurs when a baby is born with an overactive thyroid gland. Hyperthyroidism that occurs before birth is called “congenital” hyperthyroidism. Because it happens during foetal development.

The thyroid gland is a small, butterfly-shaped gland in the neck. It produces hormones that regulate the body’s metabolism. 

This system converts food into energy. This allows our brain and other organs to function. A healthy metabolism also helps the body maintain:

a healthy temperature heart rate energy level growth rate

In congenital hyperthyroidism, the thyroid gland produces too many hormones. This results in increased metabolism. 

If your child is not making enough thyroid hormones, it can cause serious problems. Treat this condition as soon as possible to lower the chance of these long-term effects.

Congenital Hyperthyroidism Causes

Congenital hyperthyroidism can happen for a variety of reasons. According to Boston Children’s Hospital, there are several possible causes of hyperthyroidism.

Graves Disease

This is an autoimmune disorder that affects the thyroid gland. In people with Graves disease, the immune system attacks the thyroid. They are causing it to make too much thyroid hormone. This can lead to various symptoms, including weight loss, anxiety, and heart palpitations.

Graves disease is more common in women than men and often runs in families. People with Graves disease are also more likely to have other autoimmune disorders. Such as type 1 diabetes or rheumatoid arthritis.

Graves disease has no cure, but medication can help treat it. In severe cases, surgery may be necessary to remove the thyroid gland.

Neonatal Graves Disease

This is a congenital form of hyperthyroidism that affects newborns. Maternal antibodies transfer from the placenta to the fetus. This leads to the overproduction of thyroid hormones. Symptoms include tachycardia, goitre, and irritability. 

Autonomous Thyroid Nodules (Toxic or Hot Nodules)

These growths in the thyroid gland produce too much thyroid hormone. Autonomous thyroid nodules are usually benign. But in rare cases, they can be cancerous.


This condition occurs when the thyroid gland becomes inflamed. Symptoms range from mild to severe. In some cases, it may be an autoimmune disorder. For newborns, it is usually temporary and goes away on its own within eight to 12 weeks. 

Congenital Hyperthyroidism Symptoms

Since congenital hyperthyroidism occurs when the thyroid gland doesn’t develop properly, or if it develops in an abnormal location, this can cause the thyroid to produce too much thyroid hormone. Now leads to the following symptoms:

  • Tiredness and weakness
  • Increased appetite and weight gain
  • Rapid heart rate, palpitations, or irregular heartbeat
  • Difficulty breathing or swallowing (dysphagia)
  • Excessive sweating (hyperhidrosis)
  • Heat intolerance

For babies, symptoms can manifest through physical features. Here are the features at birth that could develop in their first few months of life.

A puffy-looking face Large, thick tongue Large soft spots on the skull Hoarse cry Distended stomach with outpouching of the belly button (umbilical hernia) Feeding problems, including needing to wake them up for feedings and difficulty swallowing Constipation “Floppy” (poor muscle tone, also called hypotonia) Jaundice (a yellow appearance on the skin and eyes)

How Is Congenital Hyperthyroidism Diagnosed?

It is hard to figure out if a baby has a thyroid problem. But it’s easier by testing the baby’s blood. The baby has congenital hyperthyroidism if there is no thyroid hormone in the blood.  

A physical examination also helps in diagnosis. Doctors check your baby’s growth and development. They also check reflexes, muscle tone, and breathing.

Here are the tests that doctors use:

  • Newborn screening test
  • Thyroid function tests
  • Sometimes imaging tests

Congenital Hyperthyroidism Treatment

Several treatment options are available for congenital hyperthyroidism. This includes medication, surgery, and radioactive iodine therapy. The best course of treatment will depend on the severity of the condition and the child’s age. Even with congenital hyperthyroidism, children can lead healthy lives. That’s if diagnosed and treated early.

Congenital Hyperthyroidism Possible Complications

The most common complications of congenital hyperthyroidism are:

Narrow Esophagus

A narrow oesophagus means the tube connecting your mouth and stomach is too small. Food cannot pass through easily. This can cause problems with swallowing, eating, and digestion.

If your child has a rare condition that makes it hard to eat and drink, don’t let them eat too much at one time. This can lead to choking or vomiting. Try feeding your child smaller amounts more often throughout the day. And this instead of one large meal at night. This helps prevent choking or vomiting during sleep. It’s when the oesophagus relaxes due to an empty stomach.

Weak voice

A weak voice is a common complication of congenital hyperthyroidism. It’s an effect of the overproduction of thyroid hormones. This causes the vocal cords to become stiffer and less responsive. This can lead to voice loss and strain. If you have this condition, speak with your doctor. Talk to them about preventing further complications and better communication function.

Heart Problems

Heart problems associated with congenital hyperthyroidism include tachycardia. It’s a fast heart rate that is abnormal and arrhythmias (irregular heart rhythms). These can be serious and even life-threatening. If you have congenital hyperthyroidism, ask a doctor to check you. Make sure your heart is healthy. 

Muscle Weakness

The muscles may become weak and flabby and have difficulty contracting. This can lead to problems with movement and balance. In severe cases, the entire muscles may waste away.

Bone Loss

Bone loss is one of the potential complications of congenital hyperthyroidism. When the condition is not treated, it can lead to a loss of bone density and an increased risk of fractures. The most common symptom of bone loss is bone pain. Other symptoms include fatigue, weakness, and a decrease in activity level.

Heat Intolerance and Sweating

Heat intolerance is a common symptom of hyperthyroidism. This is because the thyroid gland regulates the body’s temperature. And an overactive thyroid can cause the body to overheat. 

Sweating is another common symptom of congenital hyperthyroidism. This is because the body uses sweat to regulate its temperature. And an overactive thyroid can cause the body to sweat so much. 

In severe cases, congenital hyperthyroidism can lead to heat stroke. This can be fatal. 

Mental Retardation

Mental retardation is a developmental disability that affects thinking, learning, and communication ability. Babies with congenital hyperthyroidism risk mental retardation. The condition can interfere with normal brain development. If untreated, congenital hyperthyroidism can cause permanent damage to the brain. And other organs.


The most common cause of death in congenital hyperthyroidism is heart failure. The overactive thyroid causes the heart to work harder. It leads to enlargement and eventual failure. 

Some children with hyperthyroidism may have other issues such as eye problems or hearing loss. These problems could be the effects of high levels of thyroid hormone in their bodies. Or by medications used to treat hyperthyroidism. Early diagnosis and treatment are essential to preventing these complications.

How to Live With Congenital Hyperthyroidism?

Living with congenital hyperthyroidism can be challenging. But managing the condition and leading a healthy life is possible. The most important thing is to get regular medical checkups. And follow the doctor’s recommendations. Your child may also need to take medication to control their symptoms. Also, eat a healthy diet and get plenty of exercise. By following these tips, they can live with congenital hyperthyroidism. And enjoy a good quality of life.

Stanford Children’s Health, MedlinePlus, American Thyroid Association, Children’s Hospital

Here at theAsianparent Singapore, it’s important for us to give information that is correct, significant, and timely. But this doesn’t serve as an alternative for medical advice or medical treatment. theAsianparent Singapore is not responsible for those that would choose to drink medicines based on information from our website. If you have any doubts, we recommend consulting your doctor for clearer information.

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