Newborn Babies Can Have Congenital Hypothyroidism

Question: I am the mother of four beautiful children. Our three younger ones were found to have low thyroid function within several days after they were born. They were treated immediately with thyroid medication. We are very fortunate that they have all done well in school. I was found to have thyroid problem shortly after the birth of our youngest child. My thyroid was not working and I have to take thyroid medicine also. Recently our oldest daughter complained that she was tired all the time. She has always been healthy and has had no thyroid problem. Should I get her checked also? Is there any reason why so many of us have thyroid disease?

Answer:

You are very fortunate indeed that your three younger children were found to have low thyroid function (also called hypothyroidism) shortly after they were born. With universal screening of all newborns in Canada, we are able to detect a number of common congenital problems very effectively with a few drops of blood. The thyroid function is one of the tests included in the screening.

Before these screening tests were available, babies born with low thyroid function like your children were completely missed after birth. They appeared to be entirely normal when they were born. These babies might be a bit sleepier, a little slower in nursing, passed less stool, or a little more floppy. They had lower temperature, but only if someone checked it, otherwise it would go undetected. The jaundice that happens to most newborn babies would last a little longer. However, there were no obvious signs for physicians and nurses to suspect something could be seriously wrong with these babies.

Thyroid hormone is very important in the growth and development of brain cells in infants and young children. Even though babies with low thyroid function appear normal physically, their brains cannot develop properly without adequate amount of thyroid hormone.

Unfortunately their condition was often not recognized until they were at least several months of age, when the family or physician noticed there was significant delay in development. By this time, it was too late—the delay in brain development could not be reversed. These children would grow up with mental retardation. That is why I said you are very fortunate. Your children were diagnosed very early, and your doctor gave them the right amount of thyroid hormone. As a result, their brains can develop to their full potential.

It is most interesting that you developed thyroid problem after the birth of your youngest child. You may wonder whether your thyroid condition has anything to do with their problem. My suggestion is that they are related.

Adults develop hypothyroidism when their body produces antibodies against the thyroid gland. These antibodies damage the cells that produce thyroid hormone. After a long enough time, usually several years, the amount of thyroid hormone produced by the thyroid gland will not be able to meet the need of the body. At this stage, the person will develop symptoms of hypothyroidism, including lack of energy, feeling cold, losing hair, dry skin, and constipation.

With these symptoms, physicians can do blood tests to check the thyroid function. As I mentioned earlier, there is often a delay of several years from the onset of thyroid problem to actual diagnosis.

It is quite possible that when you were pregnant with your three younger children, you already have thyroid antibodies in your body. These antibodies can pass through the placenta to the foetus during pregnancy. Although we don’t have definitive proof, your thyroid antibodies might be responsible for the thyroid problem in your three young children.

Your present concern is your eldest daughter. You may already know that thyroid problem has a very strong genetic tendency, and it is much more common in girls and women. Your daughter may be developing the same type of hypothyroidism. It is wise to have her checked by your doctor. Of course, there are many other reasons for her being tired, and your doctor can look into these also.

I hope you have a better understanding of the thyroid problems in your family. Luckily a simple thyroid pill can treat this condition easily. It is, however, very important to monitor the thyroid function regularly to make sure that the proper amount of thyroid hormone is being used. Too much or too little medicine is not good for the body.