Jill M. Rafalko, Vivian Weinblatt, Samantha Caldwell, John Tynan, Eyad Almasri, Ron McCullough2

Hricik M, Hill H, Lyon E, Noeth D

Fissell K, Schlenker E, Badura M

Mann D, Kessler L, Smith K, Donnenfeld A

Francisco E, Rayburn R, Pintzov A, Follmer Blanchard J

Gong P, Pelletier M, Silverman N, Wallerstein R

Petrarca L, Schmeidler K, Caldwell S

Nagakura H, Lichtenstein H

Schlenker E, Badura M, Fissell K

Fanelli K, Soster E, Rafalko J

This Practice Bulletin was developed by the American College of obstetricians andGynecologists’Committee on Practice Bulletins—Obstetrics and Committee on Genetics, and the Society for Maternal-Fetal Medicine in collaborationwithNancy C. Rose,MD, and Anjali J.Kaimal, MD, MAS, with the assistance of Lorraine Dugoff, MD, and Mary E. Norton, MD, on behalf of the Society for Maternal-Fetal Medicine.

Qiandong Zeng, Natalia T. Leach, Zhaoqing Zhou, Hui Zhu, Jean A. Smith, Lynne S. Rosenblum, Angela Kenyon, Ruth A. Heim, Marcia Eisenberg, Stanley Letovsky & Patricia M. Okamoto

Samantha Caldwell, Katelynn Sagaser, Zoe Nelson, Jennifer Frey, Jenna Wardrop, Theresa Boomer, Ron McCullough, Stuart Schwartz

Jason Chibuk, Jill Rafalko, Theresa Boomer, Ron McCullough, Graham McLennan, Philip Wyatt, and Eyad Almasri

Margriet Johansen, MS, CGC; Christine Riordan, MS, CGC; Inder K. Gadi; PhD, FACMG; Peter R. Papenhausen; PhD, FACMG; Stuart Schwartz, PhD, FACMG. Laboratory Corporation of America®, Center for Molecular Biology and Pathology, Department of Cytogenetics, Research Triangle Park, NC