Quiz Ref IDCarrier screening for selected recessive mendelian conditions has long been recommended as part of preconception care. Now in wider use, panethnic and expanded panels will likely identify more prospective parents who are carriers.¹ (PGD) is a powerful genetic test of embryos available to persons at risk for having a child with a genetic condition (eg, cystic fibrosis), which can help establish an unaffected pregnancy. In combination with in vitro fertilization (IVF), embryos free of the disease-causing mutation(s) are selected for intrauterine transfer, avoiding the occurrence of the genetic condition in the fetus.