Congenital anomalies are morphologic defects that are present at birth, but some, such as cardiac defects and renal anomalies, may not become clinically apparent until years later. The term congenital does not imply or exclude a genetic basis for the birth defect.

It is estimated that about 3% of newborns have a major anomaly, defined as an anomaly having either cosmetic or functional significance. They are the most common cause of mortality in the first year of life and contribute significantly to morbidity and mortality throughout the early years of life.

Classification

 developmental anomalies

• malformations
• malformative syndromes

 genetic metabolic diseases
 congenital infections

• congenital syphilis

 congenital tumors (neonatal tumors)