title: Pre- and post-test genetic counseling for chromosomal and Mendelian disorders.
abstract: Genetic carrier screening, prenatal screening for aneuploidy, and prenatal diagnostic testing have expanded dramatically over the past 2 decades. Driven in part by powerful market forces, new complex testing modalities have become available after limited clinical research. The responsibility for offering these tests lies primarily on the obstetrical care provider and has become more burdensome as the number of testing options expands. Genetic testing in pregnancy is optional, and decisions about undergoing tests, as well as follow-up testing, should be informed and based on individual patients' values and needs. Careful pre- and post-test counseling is central to supporting informed decision-making. This article explores three areas of technical expansion in genetic testing: expanded carrier screening, non-invasive prenatal screening for fetal aneuploidies using cell-free DNA, and diagnostic testing using fetal chromosomal microarray testing, and provides insights aimed at enabling the obstetrical practitioner to better support patients considering these tests.
authors.affiliation: Department of Obstetrics and Gynecology, The George Washington University, 2150 Pennsylvania Ave, NW Washington, DC 20037. Electronic address: jill.fonda.cgc@gmail.com.
authors.forename: Jill
authors.initials: J
authors.lastname: Fonda Allen
authors.affiliation: Genetic Support Foundation, Olympia, WA; Providence Health & Services, Olympia, WA.
authors.forename: Katie
authors.initials: K
authors.lastname: Stoll
authors.affiliation: Division of Translational Medicine and Human Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA.
authors.forename: Barbara A
authors.initials: BA
authors.lastname: Bernhardt
mesh_terms: D000782:Aneuploidy; D025063:Chromosome Disorders / Q000175:diagnosis*; D004247:DNA / Q000097:blood; D005260:Female; D005333:Fetus / Q000378:metabolism; D005817:Genetic Counseling / Q000379:methods*; D030342:Genetic Diseases, Inborn / Q000175:diagnosis*; D005820:Genetic Testing / Q000379:methods; D006801:Humans; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods*
chemical_list: D004247:DNA
keywords: Cell-free DNA screening; Chromosome microarray; Genetic carrier screening; Genetic counseling; Non-invasive prenatal screening; Prenatal diagnosis