1. From the Fetal Maternal Medicine Unit, Department of Obstetrics and Gynecology (K.M., B.T.), and Department of Cardiology and Cardiothoracic Surgery (K.M., G.R.S.), St Georges Hospital, University of London, London, United Kingdom; Department of Obstetrics and Gynecology (K.M., M.L.), University of Chieti, Chieti, Italy.