1 Department of Obstetrics and Gynaecology, IRCCS San Raffaele Scientific Institute; and Vita-Salute San Raffaele University, Milan, Italy.
2 Division of Obstetrics and Prenatal Medicine, Department of Medicine and Surgery (DIMEC), Istituto di ricovero e cura a carattere scientifico Azienda Ospedaliero-Universitaria di Bologna, Italy.