1. Mother-Infant Department, Obstetric Unit; University of Modena and Reggio Emilia; Modena Italy
2. Obstetric Unit; Ospedale Infermi Rimini; Rimini Italy
3. Obstetrics and Gynecology Unit; Azienda Ospedaliero-Universitaria S.Anna; Ferrara Italy
4. School and Division of Allergology and Clinical Immunology; University of Messina; Messina Italy