Role of second-trimester genetic sonography after down syndrome screening

Kjersti M. Aagaard-Tillery, Fergal D. Malone, David A. Nyberg, T. Flint Porter, Howard S. Cuckle, Karin Fuchs, Lisa Sullivan, Christine H. Comstock, George R. Saade, Keith Eddleman, Susan Gross, Lorraine Dugoff, Sabrina D. Craigo, Ilan E. Timor-Tritsch, Stephen R. Carr, Honor M. Wolfe, Diana W. Bianchi, Mary E. D'Alton