Growth HormOne Research SocietyLecture by Dr. (Prof.) I. P. S. Kochar
Paediatric & Adolescent Endocrinologist & Diabetologist
Thyroid problems are more common in adults than children, but there are some special features of childhood thyroid disorders that differ from adults.When parents are told their child has a thyroid problem there can be the temptation to attribute all subsequent medical problems to their child’s thyroid disorder. Remember that a child with thyroid problems will experience many of the same ups and downs of growing up as children without thyroid problems.
The thyroid gland is found in the neck just above the sternum (breastbone), below the larynx (‘Adam’s apple’) and is partly covered by the two strong neck muscles called the stern mastoids. It has two lobes, which in adults are about 5 cm (2 inches), long and the whole gland weighs about 25 grams (just under 1 oz.). In children it is proportionally smaller. The two lobes of the thyroid gland are joined by a central part, which lies over the windpipe (trachea). The thyroid gland can be felt quite easily in older children but not in babies.
The thyroid gland makes and releases two hormones – triiodothyronine and thyroxin. It also stores iodine, which is needed to make the thyroid hormones. Foods that contain iodine include fish, shellfish, seaweed and some vegetables. If there is not enough iodine in the diet, the thyroid gland enlarges and can produce a swelling in the neck which is called a goiter.
When the thyroid gland is poorly developed or absent, it is unable to produce the thyroid hormones (T3 and T4) and the levels in the blood become low or even undetectable. This condition is called hypothyroidism.
| 1. | Hypothyroidism which is present from birth is called congenital hypothyroidism. |
| 2. | Hypothyroidism that develops later in a child's life is called late onset or acquired hypothyroidism. |
Congenital hypothyroidism occurs in about 1 in every 3000 – 4000 babies. It is usually the result of something going wrong with the development of the thyroid gland, but the reasons for this are still not fully understood. If occurs more commonly in girls that boys, and seems to be more common in people of Asian origin.
Hypothyroidism is usually caused when the thyroid gland does not reach its proper position at the base of the neck while the baby is developing in the womb. The gland remains at the back of the tongue and this is called an ectopic thyroid. In some children with an ectopic thyroid gland it does not develop fully and in other it completely fails to develop, a condition called thyroid agenesis.
In a small proportion (about 15%) of babies with hypothyroidism, the thyroid gland is present and may even be enlarged, but it fails to produce thyroxin. This form of congenital hypothyroidism is much more likely to be inherited and is called a dyshormonogenesis, which means there is a block that prevents the hormones being produced.
Symptoms include slow feeding, sleepiness, constipation and prolonged jaundice after birth. Unfortunately, these are very common symptoms in babies, even when they do not have hypothyroidism, and so there used to be a long delay before the diagnosis was confirmed. If the diagnosis is not made early on, a child’s development may be delayed. Thus, most centre now screened at birth for congenital Hypothyroidism, which is described on Additional physical characteristics typical in babies with hypothyroidism are mottled skin, protruding tongue, thin hair and umbilical hernia (a protruding "belly button").
For Appointment :
