HYPOTHYROIDISM
Congenital hypothyroidism is a deficiency in thyroid hormone which may start before birth, at birth or shortly thereafter. There are two kinds of congenital hypothyroidism: Goitrous and Nonggoitrous.
- Goitrous:
- this may result from an inborn error of thyroxine synthesis or from drugs ingested by the mother during pregnancy.
- drugs like iodides may traverse the placental barrier and may cause goiter formation in the fetus or infant.
- Nongoitrous:
- may be due to absent or hypoplastic thyroid gland
Clinically, congenital hypothyroidism may not be very evident in the newborn. The early features are frequently seen in the first four to six weeks of life and by the second to third month more convincing manifestations may already be evident. The following are the commonly seen features: prolonged gestation with large birth size, large anterior fontanel, respiratory distress, hypothermia, peripheral cyanosis, hypoactivity, poor feeding, delayed onset of stooling, abdominal distention, vomiting, protracted jaundice, edema,
Classically, the infant may have the following: eyes which appear far apart, swollen eyelids, narrow palpebral tissues, broad nose with depressed bridge, open mouth with thick broad tongue,
The mother will usually notice that her infant is unusually quiet even when wet and feeds poorly.
The older child will present a classic picture of disproportionate dwarfism in which instance the ratio of the upper segment and lower segment is greater than normal for the child’s age.
The prognosis of congenital hypothyroidism depends upon how early the diagnosis is made and how early or late the treatment has been started.
This is the importance of Newborn Screening. In this test, congenital hypothyroidism is being screened, too. If being diagnosed and treatment is delayed beyond three to six months, then an irreversible mental retardation may occur. Intelligence is much greater if treatment is started before the age of three months.
It is much better to save a hypothyroid fetus from brain damage if treatment is given during pregnancy.