Should Clinicians Leave “Expanded” Carrier Screening Decisions to Patients?

Many patients choose to undergo some type of carrier screening when pregnant or planning to become pregnant."Expanded" carrier screening products test all patients for the same conditions, regardless of family history, race, or ethnicity.Proponents of expanded screening argue that testing everyone for everything can identify more couples at risk of having an affected fetus.However, most conditions on expanded carrier screening panels do not adhere to criteria recommended by professional organizations and can leave patients with a positive test result but little helpful information about actual clinical risk for their future baby.Confusion persists about whether clinicians should leave carrier screening decisions to patients. Need for More Accurate Carrier ScreeningMany patients choose to undergo reproductive genetic testing either when they are planning to become pregnant or once they are pregnant.1,2 One type of reproductive genetic test is carrier screening, used to identify people at risk of having a child with an autosomal recessive or X-linked recessive genetic condition.If both the woman and her male partner are found to be carriers, the child has a 25% chance of being affected by the disease and a 50% chance of being a carrier.But genetic testing can be expensive and cause patients anxiety as they wait for preliminary or confirmatory test results.In an attempt to balance these concerns with the clinical utility of test results, professional organizations such as the American College of Medical Genetics and Genomics (ACMG) and the American College of Obstetricians and Gynecologists (ACOG) generally recommend offering carrier screening on the basis of family history (ie, an affected blood relative), affected race or ethnicity (eg, Tay-Sachs disease screening in Ashkenazi Jews or sickle cell disease screening in African Americans), or because the condition is deemed worthy of universal screening (eg, cystic fibrosis in the United States) (see Table ).3,4 Receiving positive test results can have serious clinical implications for patients, 5 including invasive confirmatory testing if available for the condition (eg, chorionic villus sampling, amniocentesis, or fetal sequencing) or even pregnancy termination (a decision often constrained by state law, 6 such as before 24 weeks).It is therefore critical that patients receive timely genetic