Eric Jauniaux1, Robert M Silver2, Shigeki Matsubara3. 1. EGA Institute for Women's Health, Faculty of Population Health Sciences, University College London, London, UK. 2. University of Utah School of Medicine, Salt Lake City, UT, USA. 3. Department of Obstetrics and Gynecology, Jichi Medical University, Shimotsuke, Tochigi, Japan.