title: Twin anemia polycythemia sequence from a prenatal perspective.
abstract: OBJECTIVE
  To describe the prevalence, management and outcome of spontaneous twin anemia polycythemia sequence (TAPS) diagnosed in the prenatal period.
  
  
  METHODS
  Retrospective analysis of 142 consecutive monochorionic twin pregnancies not diagnosed with twin to twin transfusion syndrome. TAPS cases were identified based on the presence of discordant middle cerebral artery peak systolic velocity (MCA-PSV) measurements and signs suggestive of a chronic intertwin transfusion imbalance: either an elevated reticulocyte count in the anemic twin or the presence of few small unidirectional anastomoses during fetoscopy or at postnatal placental examination.
  
  
  RESULTS
  Three cases were identified, giving an estimated prevalence of 2%. Prenatal interventions were tailored to the characteristics of each case and consisted of intrauterine transfusion and interruption of the shared circulation by cord coagulation or laser separation.
  
  
  CONCLUSIONS
  In monochorionic twin pregnancies, TAPS is an uncommon prenatal finding. Nonetheless, its incidence seems high enough to recommend screening for this disease by MCA-PSV measurements.
authors.affiliation: Department of Obstetrics and Gynecology, University Hospitals, Leuven, Belgium.
authors.forename: Léonardo
authors.initials: L
authors.lastname: Gucciardo
authors.forename: Liesbeth
authors.initials: L
authors.lastname: Lewi
authors.forename: Pascal
authors.initials: P
authors.lastname: Vaast
authors.forename: Marzena
authors.initials: M
authors.lastname: Debska
authors.forename: Luc
authors.initials: L
authors.lastname: De Catte
authors.forename: Tim
authors.initials: T
authors.lastname: Van Mieghem
authors.forename: Elisa
authors.initials: E
authors.lastname: Done
authors.forename: Roland
authors.initials: R
authors.lastname: Devlieger
authors.forename: Jan
authors.initials: J
authors.lastname: Deprest
mesh_terms: D000328:Adult; D000751:Anemia, Neonatal / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000601:surgery; D001163:Arteriovenous Anastomosis / Q000000981:diagnostic imaging / Q000601:surgery; D001530:Belgium / Q000453:epidemiology; D001805:Blood Transfusion, Intrauterine; D004200:Diseases in Twins / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000601:surgery; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D017075:Laser Coagulation; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging*; D016104:Oligohydramnios / Q000000981:diagnostic imaging; D010922:Placenta Diseases / Q000000981:diagnostic imaging*; D011086:Polycythemia / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000601:surgery; D011247:Pregnancy; D015995:Prevalence; D012212:Rheology; D013577:Syndrome; D016216:Ultrasonography, Prenatal