These tests can be done within a few days so that treatment can be started promptly if needed. The effects of hypothyroidism are seen in different ways in different babies. The baby's skin may be pale or blotchy, especially when undressed. The hypothyroid baby may be uninterested in taking the bottle or breast, and may be difficult to keep awake during feedings. He or she may be severely constipated and may hold on to gas in the stomach.
Hypothyroid babies are often large as newborn infants.
If their hypothyroidism is not corrected, they generally have poor growth and poor weight gain after birth. Babies with hypothyroidism may have a slow heart rate and low blood pressure. The hands and feet may be cool to the touch due to poor circulation. Babies with hypothyroidism are often quiet and seldom cry. They may seem uninterested in the sights and sounds around them.