[1] Kaiser Permanente Northern Calif, Dept Obstet & Gynecol, San Francisco, CA USA
[2] Kaiser Permanente Northern Calif, Div Res, Oakland, ON, Canada
[3] Kaiser Permanente Northern Calif, Reg Fetal Pathol Serv, Oakland, ON, Canada
[4] Kaiser Permanente Northern Calif, Dept Obstet & Gynecol, Oakland, CA USA
[5] Kaiser Permanente Northern Calif, Dept Pediat, Santa Clara, CA USA
[6] 125 Paterson St,CAB 2nd Floor, New Brunswick, NJ 08901 USA