< Back to Previous Page New York Pregnancy Birth Defect Facts A birth defect is a problem that happens while the baby is developing in the mother's body. Most birth defects happen during the first three months of pregnancy. Birth defects vary from mild to severe, can be easy to see or require special tests, and can affect how the body looks, functions, or both. Birth defects can be found before birth, at birth, or anytime after birth, but most defects are found within the first year of life. The Congenital Malformations Registry (CMR) of the New York State Department of Health (DOH) is a repository for case reports on children who are born or reside in New York State and are diagnosed before the age of two years with any structural, functional or biochemical abnormality determined genetically or induced during gestation and not due to birthing events. Birth defects affect about one in every 33 babies born in the United States each year. Birth defects are the leading cause of infant deaths, accounting for more than 20 percent of all infant deaths. Babies born with birth defects have a greater chance of illness and long-term disability than babies without birth defects. Some women have a higher chance of having a child with a birth defect, e.g., women over 35 years have a higher chance of having a child with Down Syndrome than younger women; and certain drugs, tobacco and alcohol use during pregnancy can increase the chance of birth defects. Sometimes birth defects have no apparent cause.