Expanded Carrier Screening.

Prenatal carrier screening has expanded to include a larger number of genes and variants offered to all couples considering or with an ongoing pregnancy. Panethnic screening for cystic fibrosis and spinal muscular atrophy and screening for a limited number of conditions based on ethnicity are recommended by the American College of Obstetricians and Gynecologists. Residual risk calculations have become an obsolete part of posttest counseling when expanded carrier screening (ECS) is selected. The Perception of Uncertainties in Genome Sequencing scale offers a useful understanding of the pretest and posttest counseling concerns that should be considered as part of ECS implementation.