title: Doppler umbilical artery studies in the twin-twin transfusion syndrome.
abstract: Eleven patients with twin pregnancies were identified as having twin-twin transfusion syndrome on the basis of like-sex twins with monochorionic placentation and umbilical venous blood hemoglobin differences exceeding 50 g/L at delivery. Umbilical artery velocity-time waveform studies had been performed in these pregnancies as part of a large series of 456 twin pregnancies. In all 11 cases, the systolic-diastolic (S-D) ratio differences between the twins were less than 1 unit (mean 0.4 +/- 0.2), indicating that in twin-twin transfusion, umbilical artery S-D ratios are concordant even in the presence of discordancy in fetal size.
authors.affiliation: Department of Obstetrics and Gynecology, University of Sydney, Westmead Hospital, New South Wales, Australia.
authors.forename: W B
authors.initials: WB
authors.lastname: Giles
authors.forename: B J
authors.initials: BJ
authors.lastname: Trudinger
authors.forename: C M
authors.initials: CM
authors.lastname: Cook
authors.forename: A J
authors.initials: AJ
authors.lastname: Connelly
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity; D005260:Female; D005330:Fetofetal Transfusion / Q000097:blood / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D011247:Pregnancy; D011296:Prenatal Diagnosis; D014463:Ultrasonography; D014469:Umbilical Arteries / Q000000981:diagnostic imaging*
chemical_list: D006454:Hemoglobins