[1] Univ Oxford, Nuffield Dept Obstet & Gynaecol, Oxford, England
[2] John Radcliffe Hosp, Womens Ctr, Oxford Fetal Med Unit, Oxford, England
[3] Cristo Re Hosp, Dept Obstet & Gynaecol, Rome, Italy
[4] Univ Oxford, Oxford Grp Childrens Potential, Dept Expt Psychol, Oxford, England