Modern childbearing has brought with it new and expanding reproductive testing options that provide women with previously unavailable information about their pregnancies. Of the three to four percent of babies born with recognizable birth defects most are born in families without identified risk factors. Because women are concerned about the health and well being of the fetus, prenatal screening and/or diagnosis is offered to all women early in pregnancy. About 70% of women in the United States have maternal serum screening and/or ultrasound to detect risks for common birth defects during their pregnancy.