1 Research Center for Reproductive Medicine, Gynecological Endocrinology and Menopause, Obstetrics and Gynecology Unit, IRCCS San Matteo Foundation, Department of Clinical, Surgical, Diagnostic and Pediatric Sciences, University of Pavia, Pavia 27100, Italy. Electronic address: renappi@tin.it.
2 Division of Obstetrics and Gynecology, Department of Clinical and Experimental Medicine, University of Pisa, Pisa 56126, Italy.