bjective: To review a 12-year experience of the world’s three largest preimplantation genetic diagnosis PGD) centers. esign: Multicenter analysis of the clinical outcome of PGD. etting: In vitro fertilization programs at the Reproductive Genetics Institute, Chicago, Illinois; Saint arnabas Medical Center, West Orange, New Jersey; and SISMER, Bologna, Italy. atient(s): Poor-prognosis IVF patient...