1. Obstetric Unit, Foundation IRCCS San Gerardo dei Tintori, 20900 Monza, MB, Italy
2. School of Medicine and Surgery, University of Milan-Bicocca, Via Cadore 48, 20900 Monza, MB, Italy
3. Neonatal Intensive Care Unit, Foundation IRCCS San Gerardo dei Tintori, 20900 Monza, MB, Italy
4. Microbiology Unit, Foundation IRCCS San Gerardo dei Tintori, 20900 Monza, MB, Italy