Expanded carrier screening: what the reproductive endocrinologist needs to know.

Expanded carrier screening refers to identification of carriers of single-gene disorders outside of traditional screening guidelines. New genetic testing technologies allow for such screening at costs that are comparable to single-gene testing. There is a high degree of variability among genetic testing laboratories as to the inclusion of different disorders, some of which have mild or unpredictable phenotypes. This review discusses the pros and cons of using expanded carrier screening in the preconceptional patient and reviews guidelines currently endorsed by professional organizations.