Everything parents need to know about thyroid disease

There are a number of illnesses and conditions that new parents should be aware of. One of them is an under-functioning thyroid gland.

Hypothyroidism is a condition that can affect newborn babies, and if undetected and left untreated, it can affect your child’s development, with varying degrees of severity. Below is some insight on thyroid disease from Merck, the global pharmaceutical company headquartered in Germany.

What does the thyroid gland do?

It may be just a small, butterfly-shaped gland in your neck, but the thyroid gland produces hormones that are essential for metabolism. It is important for physical growth and maturation of the central nervous system and skeleton.

Causes of hypothyroidism in babies

There are many causes of hypothyroidism, the most relevant being congenital hypothyroidism, i.e. when an infant is born without a thyroid gland or if the gland cannot manufacture the thyroid hormone for a number of reasons. In areas with iodine deficiency, infants may also be prone to hypothyroidism. Since 1995, table salt is iodised in South Africa, to combat hypothyroidism due to iodine deficiency.

If a mother suffers from thyroid disease during pregnancy, this may affect her unborn foetus and the newborn baby. It is therefore important that a foetal ultrasonography is performed and the newborn evaluated by a paediatrician.

9 Signs and symptoms

1. Undiagnosed babies with hypothyroidism show a variety of symptoms, including:
2. Decreased activity
3. A large fontanelle
4. Poor feeding and low weight gain
5. Small stature or poor growth
6. Delayed developmental milestones
7. Jaundice
8. Constipation
9. A hoarse cry

The signs are generally not present at birth and only develop after the first few weeks. Quite often, affected babies are initially viewed as ‘good’, because they cry little (as they are inactive) and sleep a lot.

Affected newborns look totally normal at birth. The physical signs only develop gradually, by which time the child’s development is irreversibly affected. Obvious physical signs are often missed as they are very subtle. They can include coarse facial features, a big tongue, an umbilical hernia (when part of the intestine protrudes through the umbilical opening), mottled skin that is cool and dry, and anaemia.

Testing for hypothyroidism

“Testing for hypothyroidism in infants is as simple as a heel-prick test, usually after 2 to 3 days of age,” says Dr Kiran Parbhoo, paediatric endocrinologist at the Chris Hani Baragwanath Academic Hospital. “The test is quick and simple, and yields results quickly, equipping doctors and supporting healthcare professionals to intervene early by setting up a treatment regime.”

An alternative to heel-prick testing is the testing of cord blood at birth. The advantage of heel prick testing, however, is that it may be possible to screen for other inborn errors (as is the case in many developed countries). Detecting and managing inborn errors is cost-effective, as the treatment of such conditions is expensive if they are diagnosed later in life.

The importance of treatment

Failure to diagnose and treat hypothyroidism in an infant could lead to growth problems, heart problems and, if left untreated, severe intellectual disability.

Babies with congenital hypothyroidism on newborn screening programmes can be treated by simply administering thyroxine, which is delivered via crushed tablets included in breast milk or formula in infants, or swallowed by children as they grow older. Screening and treating congenital hypothyroidism can prevent mental disability.