What is a common feature of congenital hypothyroidism?

Congenital hypothyroidism is characterized by an underactive thyroid gland present from birth, which can lead to various physical manifestations. A common feature of this condition is an enlarged abdomen, or abdominal distension, often due to the accumulation of fluid and the effects of poor metabolic regulation.

In children with congenital hypothyroidism, the lack of thyroid hormones can lead to a variety of issues, including an increase in body weight and a decrease in muscle tone, which can contribute to an enlarged abdomen. This condition is also associated with other signs of hypothyroidism, such as lethargy, hypotonia, and possibly constipation, which can further impact gastrointestinal function and abdominal size.

The other options provided are not typical features associated with congenital hypothyroidism. A persistent fever, frequent respiratory infections, and severe anemia are more related to other underlying conditions or syndromes rather than directly connected to hypothyroidism. Therefore, the presence of an enlarged abdomen is the most characteristic finding associated with this condition.