1. Department of Pediatrics, Obstetrics, and Reproductive Medicine (F.P., A.I.), Division of Obstetrics and Gynecology, University of Siena, 53100 Siena, Italy;
2. Department of Physiology, Obstetrics and Gynecology, and Medicine (J.R.G.C.), University of Toronto, Toronto, Canada M5S 1A1;
3. Michael Smith Foundation for Health Research (J.R.G.C.), Vancouver, British Columbia, Canada V6H 3X8