1. From the Fetal Maternal Medicine Unit, Departments of Obstetrics and Gynecology (K.M., B.T.), and 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.