1. Department of Obstetncs and Gynecology, Harbor-UCLA Medical Center, Torrance; Department of Pediatnc Surgery, UCLA Medical Center, Los Angeles, Cahifornia
2. Department of Obstrics and Gynecology, Harbor-UCLA Medical Center, 1000 W. Carson St., Box 3, Torrance, CA 90509-2910; Department of Pediatric Surgery, UCLA Medical Center, Los Angeles, Cahifornia;