[1] Natl Univ Athens, Attikon Hosp, Dept Obstet & Gynecol 3, Athens, Greece
[2] Gen Hosp Euroclin, Athens, Greece
[3] Univ Hosp Mainz, Dept Gynecol & Obstet, Mainz, Germany
[4] Gen Hosp Metropolitan, Athens, Greece
[5] Natl Univ Athens, Sch Med, Dept Hyg Epidemiol & Med Stat, Athens, Greece