The recent introduction of clinical tests to detect fetal aneuploidy by analysis of cell-free DNA in maternal plasma represents a tremendous advance in prenatal diagnosis and the culmination of many years of effort by researchers in the field. The development of noninvasive prenatal testing for clinical application by commercial industry has allowed much faster introduction into clinical care, yet also presents some challenges regarding education of patients and health care providers struggling to keep up with developments in this rapidly evolving area. It is important that health care providers recognize that the test is not diagnostic; rather, it represents a highly sensitive and specific screening test that should be expected to result in some false-positive and false-negative diagnoses. Although currently being integrated in some settings as a primary screening test for women at high risk of fetal aneuploidy, from a population perspective, a better option for noninvasive prenatal testing may be as a second-tier test for those patients who screen positive by conventional aneuploidy screening. How noninvasive prenatal testing will ultimately fit with the current prenatal testing algorithms remains to be determined. True cost–utility analyses will be needed to determine the actual clinical efficacy of this approach in the general prenatal population.
Although noninvasive prenatal testing for aneuploidy represents a tremendous advance in genetics, currently these tests have limitations that are important to consider when implementing them into prenatal screening and diagnosis programs.
Department of Obstetrics and Gynecology, Stanford University School of Medicine/Lucile Packard Children's Hospital, Stanford, California; Intermountain Healthcare, University of Utah School of Medicine, Intermountain Medical Center, Maternal Fetal Medicine, Salt Lake City, Utah; and the Department of Genetics and Developmental Biology, University of Connecticut Health Center, Farmington, Connecticut.
Corresponding author: Mary E. Norton, MD, 300 Pasteur Drive, HH333, Stanford University/Lucile Packard Children's Hospital, Stanford, CA 94305; e-mail: firstname.lastname@example.org.
Financial Disclosure Dr. Norton is a coprincipal investigator on clinical trial NCT0145167 sponsored by Ariosa Diagnostics. The other authors did not report any potential conflicts of interest.