Congenital Hypothyroidism

What is Congenital Hypothyroidism?
Hypothyroidism refers to an underactive thyroid gland. Congenital Hypothyroidism (CH) occurs when a newborn infant is born without the ability to make normal amounts of thyroid hormone. In India, congenital hypothyroidism occurs in about 1 in 1500-2000 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, because 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 (CH) 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 hormones 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. CH 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.

How is Congenital Hypothyroidism diagnosed?
Most private hospitals in India now carry out Newborn Screening for Congenital Hypothyroidism. Screening tests are done on either umbilical cord blood or the baby’s capillary or venous blood sample after 48-72 hours of life. If the levels of TSH on this sample are high, the test is repeated on the venous sample after the 7th day of life. The doctor may order additional blood tests like Free T4 estimation along with the confirmatory TSH sample. A persistently high TSH value suggests a diagnosis of Congenital Hypothyroidism. Once a diagnosis of CH is made, a Nuclear Scan and an Ultrasound of the thyroid are done to delineate the etiology or cause of CH.