The life of a baby begins long before he or she is born. A new individual human being begins at fertilization, when the sperm and ovum meet to form a single cell. If the baby's life is not interrupted, he or she will someday become an adult man or woman. Worldwide, millions of unborn babies are killed each year. In the United States alone, over 52 million unborn babies have been killed since the Roe v Wade decision of 1973.