Congenital hypothyroidism refers to the insufficient production or secretion of the thyroid hormone in newborn babies. Many factors are responsible for causing this condition, which if not diagnosed and treated on time, can impair the neurological development of a child.
Congenital hypothyroidism (CHT) is the medical term used to signify the deficiency of thyroid hormone in newborn babies due to a malfunctioning thyroid gland. The condition is usually triggered by factors like a defect in the thyroid gland, a deficiency of iodine, or an inborn defect in the metabolism of thyroid hormone.
It is crucial to detect this condition in the early stage, so as to ensure its proper treatment. If the condition goes unrecognized, and is not treated immediately, it can impair the normal rate of growth. It can even lead to permanent mental retardation.
This endocrine disorder is of two types – permanent and transient. The permanent form is usually caused by a defect in the development of the thyroid gland, which is known as dysgenesis. It accounts for almost two-third of the total cases of congenital hypothyroidism. On the other hand, almost 10% of the total cases are caused by a defect in the formation, as well as secretion of the thyroid hormone, thyroxine. This is largely an inherited defect. The secretion of the thyroid hormones is controlled by the hypothalamus and the pituitary gland, and so a problem in any of these parts may also cause hypothyroidism.
Transient congenital hypothyroidism often results from a deficiency of iodine, probably due to the insufficient intake of iodine by the mother. If a mother is afflicted by the autoimmune thyroid disease (a disease, where the body’s own immune system attacks the thyroid gland), the antibodies known as TSH (thyroid-stimulating hormone) receptor-blocking antibodies, may pass over to the fetus through the placenta. These antibodies can impair the functions of the thyroid gland in a newborn baby. Apart from these, this condition can be caused by the intake of iodine in high dosage, especially if iodine-based medications are taken either by the mother or her baby. Sometimes, this type of hypothyroidism can also be associated with an error in the transportation of thyroid hormones.
Congenital hypothyroidism may not exhibit any signs or symptoms, or the symptoms may be so mild that they may not be easily recognized. Some such signs and symptoms that this condition can produce are, excessive sleeping, a hoarse cry, slow movements, feeding problems, irregular bowel movements, recurring constipation, low temperature of the body, dry skin, etc. But in severe cases, i.e., when the thyroid gland is absent, the baby can have an enlarged fontanel (a soft spot on the forehead), umbilical hernia, and a large tongue.
Diagnosis and Treatment
For the early detection of this condition, newborn babies are screened within a few days after their birth to check the levels of thyroid-stimulating hormone (TSH) and thyroxine (T4). If the level of thyroid-stimulating hormone is unusually high or the level of thyroxine is abnormally low, then further tests are carried out to find out the actual cause of this problem.
This type of hypothyroidism is treated with a daily dose of thyroxine, usually available as tablets. The tablets can be administered with a small amount of water or milk. After a few weeks, the levels of thyroid-stimulating hormone and thyroxine are checked again to evaluate the efficacy of the treatment.
Infants with congenital hypothyroidism usually have a normal rate of growth and development if the condition is diagnosed and treated at the early stage. However, some studies have disclosed minor problems in memory and attention in those children, who either received a delayed treatment or lower starting dosage of the thyroxine hormone. Therefore, the key to proper treatment is the early detection of this disorder. In order to lower the frequency of this endocrine disorder, women should take the required amount of iodine during pregnancy.
Disclaimer: This HealthHearty article is for informative purposes only, and should not be replaced for the advice of a medical professional.