As the Member of an Ethics committee that evaluates protocols for human clinical trials, I came across the excellent initiative taken up by GSK to educate the masses on neo-natal screening through their campaign named ACT – Against Congenital Hypothyroidism. The more I read about this, the more I felt it is my duty to write this post, as I am also a parent.
If there’s one thing that every expectant mother worries about, it is that her baby should be born healthy. To ensure continued health, new-borns are screened with a series of health checks so that any hidden issues that are not so obvious can be diagnosed early and treated.
What does congenital hypothyroidism have to do with this? When I read that babies born with hypothyroidism look completely normal, it scared me.
So yes, congenital hypothyroidism is something to worry about.
Let’s look at the statistics.
The prevalence of hypothyroidism in developed countries is 4-5% and a recent Indian study across eight major cities found that more than 10% adults suffer from hypothyroidism. Worldwide, congenital hypothyroidism affects 1 in 3,800 new born babies and in India, it is much worse at 1 in 2640 babies. Girls are more prone to this condition than boys.
Truth is, nobody can predict whether a child will enjoy perfect health throughout her life.
However, it is possible to make sure that early screening eliminates the possibility of undiagnosed diseases that can cause severe problems later in life. The good news is, children who are diagnosed and treated from an early age can enjoy a normal life.
If you are wondering what is congenital hypothyroidism, here’s an easy definition.
Hypothyroidism is caused by an underactive thyroid gland that does not produce sufficient thyroid hormone to help with normal mental and physical development. “Congenital” refers to the condition present at birth.
What really happens with congenital hypothyroidism?
It can be a result of a failure of the thyroid gland, absence of the thyroid gland or its location in the wrong place. As the baby develops in the womb the thyroid gland moves from the back of her tongue to its place in the neck. In some babies this does not happen and the gland stays undeveloped. In others, wrong position prevents it from functioning normally.
In these cases of congenital hypothyroidism, the risk of giving birth to another child with the same condition is low. A rarer condition is when the thyroid gland is in the right place but does not produce thyroxine as it should. This is genetic and there is a risk of siblings being born with the same condition.
Insufficient thyroid hormone causes abnormal growth and development and slow mental function.
The thyroid gland is present at the base of our neck. It produces the hormone thyroxine or T4 and helps our cells function efficiently while maintaining body temperature. In babies and children, it is critical for normal growth and brain and body development. When babies do not have enough thyroid hormone, they grow slowly, appear sluggish, have learning difficulties and other health issues.
Sometimes an iron deficiency in the mother during pregnancy can cause CH. In populations that do not get enough iodine in their diet, this is common. If the mother takes anti-thyroid medication during pregnancy, chances are her baby will be born with CH.
Why timely diagnosis and treatment is crucial
Babies born with CH do not always show symptoms, as they have some of their mother’s thyroid hormone to protect them for a few weeks. After this, they must depend on their own thyroid gland. Without enough thyroxine to grow, the symptoms begin to show up. Some of these are:
- Jaundice, yellowish skin
- Problems with feeding
- Sleeping more than usual
- Less active
- Large swollen tongue
- Dry skin, cool skin
- Large belly with a protruding navel
What if treatment is delayed, or worse, not given?
In Congenital Hypothyroidism, birth weight and length are normal, but head size may be slightly increased. Prolongation of physiologic jaundice may be the earliest sign. Feeding difficulties, especially sluggishness, lack of interest, sleepiness, and choking spells during nursing are often present during 1st month of life.
Respiratory difficulties, due in part to the large tongue may also occur. Affected infants cry little, sleep much, have poor appetites and are generally sluggish. The abdomen is large, and an umbilical hernia is usually present. The temperature is below normal, often less than 35°C, and the skin, particularly that of extremities may be cold and mottles. Swelling of the genitals and extremities may be present. Because symptoms appear gradually, the clinical diagnosis is often delayed.
Approximately 10% of infants with Congenital Hypothyroidism have other associated abnormalities. Cardiac abnormalities are most common, but abnormalities of the nervous system and eye can also be there.
This is why early screening is essential, preferably at birth. A quick blood test to check for TSH levels. (Thyroid Stimulating Hormones). If it is high, it can mean hypothyroidism.
Fortunately most children who are diagnosed and treated early live a normal life, avoiding the possibility of a low IQ and developmental problems.
Points to note
- Treatment is lifelong, as medication must be taken regularly, for life.
- Levothyroxine is the medication given to treat congenital hypothyroidism to replace the thyroxine that the baby’s thyroid gland cannot produce.
- Regular check-ups to monitor thyroxine levels to adjust medicine dosage
- Treatment is generally effective and easy.
- Taking the medication regularly and in the right dosage is important. Too much can cause hyperthyroidism with diarrhoea, restlessness, low weight gain and rapid growth. Too little causes hypothyroidism with low energy, constipation, cold extremities, unprecedented weight gain and slow growth.
What about prevention?
Most cases of CH cannot be prevented. However, the following precautions by expectant mothers help reduce the risk:
- avoid radioactive iodine treatment
- avoid iodine as antiseptic
- consume just enough iodine
Also, early detection is key. Screening of infants should be performed between two and four days of birth. If this is not possible, testing should be performed before discharge or within seven days of birth.
Since congenital hypothyroidism is not always inherited it is difficult to zero in on a specific population of pregnant women who are at risk for fetal hypothyroidism. Some pointers, however, that indicate that the fetus may be at risk, are:
- Family history where a previous infant was born with congenital hypothyroidism
- When a routine ultrasonography shows a fetal goiter
- When a pregnant woman with Graves disease undergoes treatment with antithyroid drugs
- When the mother has been exposed to radioactive iodine
What about screening in India?
Screening is a simple heel prick test available in most hospitals and laboratories. Talk to your doctor for more information.
The good news is, with early diagnosis and proper treatment in the first few weeks after birth, the baby can grow normally. A delay in diagnosis or treatment, especially during the first three years can cause brain damage. The baby must be monitored regularly even levels of thyroxine normalize. Successful treatment is simple, effective and safe.
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