Birth of a normal girl after in vitro fertilization and preimplantation diagnostic testing for cystic fibrosis

Preimplantation testing of embryos conceived in vitro may eliminate the need to terminate a pregnancy in couples with genetic disorders. Traditional prenatal testing does not take place until the the first or second trimester of pregnancy. Thus, some women may have to terminate multiple pregnancies before conceiving a healthy fetus. Three couples in which both partners had the gene for cystic fibrosis donated eggs and sperm for in vitro fertilization. Three days after fertilization, the embryos underwent genetic testing for the cystic fibrosis gene. One couple did not produce an embryo that could be implanted. Each of the other two women was implanted with one embryo that was a carrier of the cystic fibrosis gene and one unaffected embryo. One of the women gave birth to a healthy baby girl who did not have the gene for cystic fibrosis. Testing of this diagnostic technique is in the early stages, but it seems promising, at least for disorders that result from a defect in one gene.