Congenital hypothyroidism

A guide for parents

What is congenital hypothyroidism?

Hypothyroidism refers to an underactive thyroid gland. Congenital hypothyroidism occurs when a newborn infant is born without the ability to make normal amounts of thyroid hormone. Congenital hypothyroidism occurs in about 1 in 3000-4000 children, is most often permanent and treatment is lifelong. Thyroid hormone is important for your baby’s brain development as well as growth. Therefore untreated congenital hypothyroidism can lead to mental retardation and growth failure. However, as there is excellent treatment available, with early diagnosis and treatment, your baby is likely to lead a normal, healthy life.

What causes congenital hypothyroidism?

Congenital hypothyroidism most often occurs when the thyroid gland does not develop properly, either because it is missing, is too small or ends up in the wrong part of the neck. Sometimes the gland is formed properly but does not produce hormone in the right way. Also, sometimes the thyroid is missing the signal from the pituitary (master) gland which tells it to produce thyroid hormone. In a small number of cases, medications taken during pregnancy, mainly medications for treating an overactive thyroid, can lead to congenital hypothyroidism which is temporary in most cases. Congenital hypothyroidism is usually not inherited through families. This means, if one child is affected it is unlikely that other children you may have in the future will suffer from the same condition.

What are the signs and symptoms of congenital hypothyroidism?

The symptoms of congenital hypothyroidism in the first week of life are not usually obvious. However sometimes when hypothyroidism is severe, there may be poor feeding, excessive sleeping, weak cry, constipation and prolonged jaundice (yellow skin) after birth. In these babies, the doctor may find a puffy face, poor muscle strength, a large tongue with a distended abdomen and larger than normal fontanelles (soft spots) on the head.

How is congenital hypothyroidism diagnosed?

Given the difficulty in diagnosing congenital hypothyroidism in the newborn period based on signs and symptoms, all hospitals in the United States, under the supervision of state health departments, screen for this disease using blood collected from your baby’s heel before discharge from the hospital. This process is called newborn screening. When there is a positive result (a low level of thyroid hormone with a high level of TSH from the pituitary), the screening program immediately notifies the baby’s doctor, usually before the baby is 2 weeks old. Before 6728 Old McLean Village Drive