Congenital anomalies, also known as birth defects, are defined as structural or functional anomalies that exist at or before birth and are among the most common causes of neonatal morbidity and mortality. Birth defects can involve an isolated organ system or multiple organ systems; multiple anomalies may encompass a syndrome. Congenital anomalies can have medical, surgical, cosmetic, and/or social significance and may have long-term impact on the development and health of the affected individual.