[1] Paris Descartes Univ, Hop Necker Enfants Malad, AP HP, Dept Obstet & Fetal Med, Paris, France
[2] Univ Liverpool, Dept Womens & Childrens Hlth, Liverpool L69 3BX, Merseyside, England
[3] Univ Montreal, Dept Obstet & Gynaecol, Montreal, PQ, Canada
[4] Univ Montreal, CHU St Justine, Montreal, PQ, Canada
[5] Univ Tubingen, Dept Obstet & Gynecol, Tubingen, Germany
[6] Ist Giannina Gaslini, Fetal Med & Surg Unit, I-16148 Genoa, Italy
[7] KK Womens & Childrens Hosp, Dept Maternal Fetal Med, Obstet Ultrasound & Prenatal Diagnost Unit, Singapore, Singapore
[8] Univ Nottingham, Sch Clin Sci, Div Obstet & Gynaecol, Nottingham NG7 2RD, England