[1] Elena Venizelou Gen Matern State Hosp, Dept Obstet & Gynecol 3, Athens, Greece
[2] Tzaneio Gen State Hosp, Dept Pathol, Piraeus, Greece
[3] G Chatzikosta Gen State Hosp, Dept Obstet & Gynecol, Ioannina, Greece
[4] Univ Athens, Dept Obstet & Gynecol 2, Athens, Greece
[5] Hellen Ctr Dis Control & Prevent, Athens, Greece