title: Yolk sac number does not predict reliably amnionicity in monochorionic twin pregnancies: a case of a monochorionic monoamniotic twin pregnancy with two distinct yolk sacs on early first-trimester ultrasound.
authors.affiliation: The Ottawa Fertility Centre, University of Ottawa, Ottawa, Ontario, Canada. scorbett@conceive.ca
authors.forename: S L
authors.initials: SL
authors.lastname: Corbett
authors.forename: D
authors.initials: D
authors.lastname: Shmorgun
mesh_terms: D000650:Amnion / Q000000981:diagnostic imaging*; D002823:Chorion / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D059285:Pregnancy, Twin; D014430:Twins, Monozygotic; D014463:Ultrasonography; D015017:Yolk Sac / Q000000981:diagnostic imaging*