1. Departments of Obstetrics, Gynecology, and Reproductive Sciences (V.V.S., S.T., E.R.N.) Yale University School of Medicine, New Haven, Connecticut 06520;
2. Departments of Pediatrics (V.B.), Yale University School of Medicine, New Haven, Connecticut 06520;
3. Department of Cell Biology, Pediatrics, and Medicine (J.R.W.), Duke University Medical Center, Durham, North Carolina 27710;
4. Department of Pediatrics (T.M.), Vanderbilt University, Nashville, Tennessee 37235;
5. Department of Obstetrics and Gynecology (C.M.), The Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033;
6. Department of Obstetrics, Gynecology, and Reproductive Sciences (N.F.), University of California, San Francisco, San Francisco, California 94143;
7. Department of Obstetrics and Gynecology (J.S.P.), Seoul National University College of Medicine, Seoul 110-744, Korea;
8. Department of Obstetrics and Gynecology (Y.W.), First Clinical Medical College of Harbin Medical University, Harbin 150001, China