title: Which twin is which?
authors.affiliation: Department of Fetal Medicine, Queens University, Belfast and Department of Health and Life Sciences, University of Ulster, Belfast, UK. jim.dornan@belfasttrust.hscni.net
authors.forename: J C
authors.initials: JC
authors.lastname: Dornan
mesh_terms: D001722:Birth Order; D005260:Female; D006801:Humans; D011247:Pregnancy; D014427:Twins; D016216:Ultrasonography, Prenatal / Q000379:methods*