1. Department of Drug Research and Evaluation, Istituto Superiore di Sanità (ISS), Rome, Italy.
2. Department of Infectious Diseases, Catholic University, Rome, Italy.
3. University of Milan, Dept. Obstet. Gynecol., and S. Paolo Hospital, Milan, Italy.
4. Department of Obstetrics and Gynecology, University of Turin, and A.O. OIRM S. Anna, Turin, Italy.
5. University of Milan, Department of Obstetrics and Gynaecology, and Buzzi Hospital, Milan, Italy.
6. INMI L. Spallanzani, Rome, Italy.
7. University of Padova, Department of Pediatrics, Padova, Italy.
8. Department of Obstetrics and Gynaecology, Policlinic Hospital, Trieste, Italy.
9. Department of Obstetrics and Gynecology, University Federico II of Naples, Naples, Italy.
10. Unit of Infectious Diseases, Department of Internal Medicine, Spirito Santo Hospital, Pescara, Italy.
11. Department of Medical Specialties, Infectious Diseases Clinic, University of Modena and Reggio Emilia, Modena, Italy.