What is the primary characteristic of a birth defect?

The primary characteristic of a birth defect is that it is present at birth. Birth defects, also known as congenital anomalies, are structural or functional abnormalities resulting from factors that occur during prenatal development. These defects can affect various parts of the body, including the heart, brain, limbs, and other organs.

Being present at birth means that these conditions can be identified during or immediately after delivery, and some may be observed through imaging or genetic testing during pregnancy. This characteristic distinguishes them from other health conditions that can develop later in life or are acquired due to environmental factors. Understanding this concept is crucial in the study of human pathophysiology, as it highlights the importance of genetic and environmental influences on fetal development.