[1] IRCCS San Raffaele Hosp, Dept Obstet & Gynaecol, I-20132 Milan, Italy
[2] Univ Roma Tor Vergata, Dept Biomed & Prevent, I-00133 Rome, Italy
[3] Univ Vita Salute San Raffaele, Ctr Nursing Res & Innovat, I-20132 Milan, Italy
[4] IRCCS Policlin San Donato, Clin Res Serv, I-20097 Milan, San Donato, Italy
[5] Univ Vita Salute San Raffaele, Bergamo Hosp Inst, Degree Course Nursing, Policlin San Pietro, I-24036 Ponte San Pietro, Italy
[6] Univ Vita Salute San Raffaele, Degree Course Midwifery, I-20132 Milan, Italy
[7] Univ Vita Salute San Raffaele, IRRCS San Raffaele Hosp, Dept Obstet & Gynaecol, I-20132 Milan, Italy