Twin anemia polycythemia sequence (TAPS) is considered a variant of the twin to twin transfusion syndrome (TTTS). Epidemiology TAPS may occur spontaneously ...×ArticlesLogInCasesSignUpCoursesQuizDonateAbout×MenuSearchADVERTISEMENT:Radiopaediaisfreethankstooursupportersandadvertisers.BecomeaGoldSupporterandseenoads.ArticlesCasesCoursesLogInLoginSignup{"url":"/signup-modal-props.json?lang=us\u0026email="}ArticlesCasesCoursesQuizAboutRecentEditsGoad-freeSearchTwinanemiapolycythemiasequenceDrBahmanRasuli◉andRadswiki◉etal.Twinanemiapolycythemiasequence(TAPS)isconsideredavariantofthetwintotwintransfusionsyndrome(TTTS).Onthispage:Article:EpidemiologyPathologyRadiographicfeaturesReferencesImages:CasesandfiguresEpidemiologyTAPSmayoccurspontaneouslyinupto5%ofmonochorionictwinsandmayalsodevelopafterincompletelasertreatmentintwin-to-twintransfusionsyndromecases2.PathologyAswithtwin-to-twintransfusionsyndrome,theunderlyingmechanismisthoughttobeabnormalplacentalvascularanastomoses,however,inTAPStherateoftransfusionisslowandthereforeresultsinagradualdiscordanceoffetalhemoglobin,withoutthehormonaldisbalanceandsubsequentliquordiscordanceseeninTTTS.Onetwindevelopsanemiaandtheotherpolycythemia.RadiographicfeaturesAntenatalultrasoundOneofthefeaturessuggestingthediagnosisisadiscordanceinfetalmiddlecerebralarterypeaksystolicvelocity (MCA-PSV)measurements4.Incontrasttotheclassictwin-to-twintransfusionsyndrome,thereisnoamnioticfluiddiscordance (i.e.no-twinoligo-polyhydramniossequence(TOPS)) 5.References1.LoprioreE,SlaghekkeF,OepkesDet-al.Clinicaloutcomeinneonateswithtwinanemia-polycythemiasequence.Am.J.Obstet.Gynecol.2010;203(1):54.e1-5.doi:10.1016/j.ajog.2010.02.032-Pubmedcitation2.SlaghekkeF,KistWJ,OepkesDet-al.Twinanemia-polycythemiasequence:diagnosticcriteria,classification,perinatalmanagementandoutcome.Fetal.Diagn.Ther.2010;27(4):181-90.doi:10.1159/000304512-Pubmedcitation3.SuzukiS.Twinanemia-polycythemiasequencewithplacentalarterio-arterialanastomoses.Placenta.2010;31(7):652.doi:10.1