Overview | Symptoms | Treatment | Prevention
Congenital hypothyroidism
The absence of thyroid function in the newborn resulting from one of several problems or defects that can occur during pregnancy.
Hypothyroidism in the newborn may result from absence or lack of development of the thyroid gland, destruction of thethyroid gland, failure of stimulation of the thyroid by the pituitary, and/or by defective or abnormal synthesis of thyroid hormones. Absence or lack of development of the thyroid is the most common defect and occurs at a rate of 1 out of every 6,000 to 7,000 births. Girls are more often affected than boys.
Hypothyroid infants often have a distinctive appearance with a puffy-appearing face, a dull look, and a large tongue that protrudes from the mouth, which is usually kept open. They usually develop this appearance as the disease progresses. They may have dry brittle hair, low hairline and jaundice. Feeding is poor and the infant may choke frequently. Constipation is common. Affected children do not cry much, but sleep excessively and are sluggish and inactive. Muscle tone is usually decreased.
If untreated, hypothyroidism can lead to severe mental retardation and growth retardation. Development is delayed early on, often indicated by failure to meet normal milestones. The appearance of teeth may be delayed. These problems become more severe as the child ages. Growth failure in terms of body length is noted very early.
Early diagnosis is imperative. Most of the effects of hypothyroidism are easily reversible. However, critical development of the nervous system takes place in the first few months after birth. The absence of thyroid hormones may result in irreversible damage to the nervous system with marked mental retardation.
Replacement therapy with thyroxine is the standard approach to treatment of hypothyroidism. Once medication starts, the blood levels of T3 and T4 are monitored to keep the values within a normal range.
Very early diagnosis generally results in a good outcome for the infant, in terms of growth and mental capability. Newborns diagnosed and treated in the first month to month and a half generally develop normal intelligence. Absence of thyroid hormone during early life gives a poor outlook in terms of mental development.
Call your health care provider if you feel your child shows signs or symptoms of hypothyroidism or if you are pregnant and are exposed to antithyroid drugs or procedures.
Absence of the thyroid and defective thyroxine production are not preventable. Destruction of the thyroid in the fetus may occur if the mother is treated with radioactive iodine for thyroid cancer while she is pregnant. Radioiodine should be avoided unless the procedure is lifesaving. Infants of mothers taking antithyroid medications should be observed carefully after birth for evidence of drug induced transient (brief) hypothyroidism.
Most hospitals now perform a routing screening test on all newborns to detect hypothyroidism.
Note: The information provided herein should not be used for diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. There is no warranty that the information is free from all errors and omissions or that it meets any particular standard.