According to the National Center for Health Statistics, every three and a half seconds another human baby is born with a congenital anomaly. A congenital anomaly is any irregularity of function, structure, or metabolism present at birth, and over four thousand different defects have been diagnosed.
Many more defects remain undiscovered today.
Genetic inheritance and environmental sources are causes of congenital anomalies. Often times, there are a multitude of factors that combine to bring about a defect. Fetal alcohol syndrome, a condition in which the mother consumes alcohol during pregnancy and inflicts damage to the unborn child, is an example of an environmental source. Other environmental problems that destructively influence the fetus are viruses, malnutrition, drug abuse, and injury. The genetic factors are more complex in that one must study the DNA and developmental biology to fully comprehend the nature of the anomaly.