[1] Sahlgrens Univ Hosp, Dept Obstet & Gynaecol, S-41685 Gothenburg, Sweden
[2] Southmead Hosp, Bristol Urol Inst, Bristol, Avon, England
[3] Kings Coll Hosp London, Dept Obstet & Gynaecol, London, England
[4] Univ Wisconsin, Sch Med, Dept Family Med, Madison, WI USA
[5] Johannes Gutenberg Univ Mainz, Dept Urol, Urol Clin, D-6500 Mainz, Germany
[6] Univ Penn, Med Ctr, Div Urol, Philadelphia, PA 19104 USA