[1] Univ Milano Bicocca, Dept Med & Surg, Via Cadore 48, I-20900 Monza, Italy
[2] San Gerardo Hosp, Clin Obstet & Gynecol, Via Pergolesi 33, I-20900 Monza, Italy
[3] Univ Milano Bicocca, Sch Med & Surg, Ctr Biostat Clin Epidemiol, Via Cadore 48, I-20900 Monza, Italy