1. Department of Gynecology/Obstetrics (B.B., L.P., R.Z.S.), Poznan University of Medical Sciences, 60-535 Poznan, Poland
2. Department of Epidemiology and Public Health (J.D.), Yale University School of Medicine, New Haven, Connecticut 06520
3. Department of Obstetrics and Gynecology (A.J.D.), Yale University School of Medicine, New Haven, Connecticut 06520