title: Introduction.
authors.affiliation: Department of Obstetrics & Gynecology, Columbia University Medical Center, 622 West 168th St, PH 16-66D, New York, NY 10032. Electronic address: rw2191@columbia.edu.
authors.forename: Ronald J
authors.initials: RJ
authors.lastname: Wapner
authors.affiliation: Counsyl, 180 Kimball Way South, San Francisco, California 94080.
authors.forename: James D
authors.initials: JD
authors.lastname: Goldberg
mesh_terms: D000013:Congenital Abnormalities / Q000175:diagnosis*; D005260:Female; D006801:Humans; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods*