[1] UNIV CALIF SAN FRANCISCO,DEPT OBSTET GYNECOL & REPROD SCI,SAN FRANCISCO,CA 94143
[2] UNIV CALIF SAN FRANCISCO,DEPT RADIOL,SAN FRANCISCO,CA 94143
[3] UNIV CALIF SAN FRANCISCO,DEPT ANESTHESIA,SAN FRANCISCO,CA 94143
[4] UNIV TEXAS,HLTH SCI CTR,DEPT OBSTET & GYNECOL,SAN ANTONIO,TX 78284