[1] Ctr Hosp Reg Univ Lille, Dept Gynecol Surg, Lille, France
[2] Ctr Hosp Reg Univ Lille, Hop Jeanne de Flanders, Lille, France
[3] Ctr Hosp Reg Univ Lille, Dept Biostat, Lille, France
[4] CHR La Citadelle, Dept Obstet & Gynecol, Liege, Belgium
[5] Royal Sussex Cty Hosp, Dept Obstet & Gynecol, Brighton BN2 5BE, E Sussex, England