Hyperthyroidism in infants is a rare but potentially serious condition that occurs when a baby produces too much thyroid hormone. It’s usually related to maternal Graves’ disease during pregnancy.

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Hyperthyroidism happens when an infant has too much thyroid hormone. It’s usually found in babies of birthing parents with Graves’ disease, a form of hyperthyroidism.

Babies with hyperthyroidism have many signs and symptoms like irritability, feeding problems, and failure to thrive. Treatment can be effective and involves medications and, in some cases, surgery.

Hyperthyroidism in infancy is a rare and potentially life threatening condition. It happens when a baby produces too much thyroid hormone. In infants, it’s usually seen in babies of people who had Graves’ disease during pregnancy.

The signs and symptoms of hyperthyroidism in infants can be serious and include:

If an infant has hyperthyroidism while in the womb, and it isn’t detected or treated until after birth, the baby may have severe symptoms like:

The most common cause of hyperthyroidism in infants is exposure to maternal antibodies from Graves’ disease during pregnancy.

Graves’ disease during pregnancy exposes a baby to maternal antibodies that stimulate the mom’s thyroid to produce excess thyroid hormone. These thyroid antibodies cross the placenta and may cause the baby’s thyroid to also overproduce thyroid hormone – intrauterine Graves’ disease.

Graves’ disease can cause fetal death or premature delivery in the fetus. Once the baby is born, the maternal antibodies leave the baby’s body. But the rate these antibodies clear the baby’s body varies, so hyperthyroidism can last longer in some babies than others.

If there’s evidence of maternal Graves’ disease during pregnancy, the baby will be screened for hyperthyroidism.

The pediatrician will order thyroid function tests to determine if your baby’s thyroid gland is functioning properly. These blood tests measure the amount of various thyroid hormones in a baby’s blood. If there are high amounts of these hormones present, it means the baby has hyperthyroidism.

Symptoms of hyperthyroidism in infants can be vague and look like other conditions, so all babies from pregnancies that involved confirmed Graves’ disease will be screened and monitored for at least 3 to 5 days.

Since hyperthyroidism can develop later in some infants, babies will generally be tested again in 10-14 days after birth.

The treatment for hyperthyroidism in infants may include:

Infants with hyperthyroidism generally recover within 6 months but your healthcare professional will likely monitor your child.

The main risk factor for hyperthyroidism in infants is maternal Graves’ disease during pregnancy.

Infants who develop symptoms after delivery have normal thyroid levels within 6 months. Symptoms will vary depending on the amount of exposure an infant had before delivery.

Because the onset of symptoms can vary, babies will be monitored and may be tested after delivery, in the first few weeks of life, and again within the first 3 months of life.

How do I know if my baby has hyperthyroidism?

If you have a history of Graves’ disease before or during your pregnancy, doctors will order tests to determine if you and your baby, if indicated, have antibodies that raise the risk of your baby having hyperthyroidism.

The symptoms of hyperthyroidism in an infant can include:

  • feeding problems
  • vomiting and diarrhea
  • bulging eyes
  • irritability

Is hyperthyroidism curable in newborns?

Yes, most babies will have normal thyroid screen within 6 months.

Hyperthyroidism in an infant is a rare and potentially life threatening condition. It’s usually caused by exposure to prenatal maternal Graves’ disease.

Infants with symptoms or who have a parent with a history of Graves’ disease during pregnancy will be tested after birth and at several other times in the first 3 months of life.

Hyperthyroidism in infants may be treated and generally resolves in the first year of life.