Hemorrhage is the most frequent cause of severe maternal morbidity and preventable maternal mortality and therefore is an ideal topic for the initial national maternity patient safety bundle.   Main, Elliott K. MD; Goffman, Dena MD; Scavone, Barbara M. MD; Low, Lisa Kane PhD, CNM; Bingham, Debra DrPH, RN; Fontaine, Patricia L. MD, MS; Gorlin, Jed B. MD; Lagrew, David C. MD; Levy, Barbara S. MD