Consensus diagnostic criteria and monitoring of twin anemia–polycythemia sequence: Delphi procedure

Abstract

Objectives Twin anemia–polycythemia sequence (TAPS) is associated with increased perinatal morbidity and mortality. Inconsistencies in the diagnostic criteria for TAPS exist, which hinder the ability to establish robust evidence‐based management or monitoring protocols. The main aim of this study was to determine, by expert consensus using a Delphi procedure, the key diagnostic features and optimal monitoring approach for TAPS. Methods A Delphi process was conducted among an international panel of experts on TAPS. Panel members were provided with a list of literature‐based parameters for diagnosing and monitoring TAPS. They were asked to rate the importance of the parameters on a five‐point Likert scale. Consensus was sought to determine the cut‐off values for accepted parameters, as well as parameters used in the monitoring of and assessment of outcome in twin pregnancy complicated by TAPS. Results A total of 132 experts were approached. Fifty experts joined the first round, of whom 33 (66%) completed all three rounds. There was agreement that the monitoring interval for the development of TAPS should be every 2 weeks and that the severity should be assessed antenatally using a classification system based on middle cerebral artery (MCA) peak systolic velocity (PSV), but there was no agreement on the gestational age at which to start monitoring. Once the diagnosis of TAPS is made, monitoring should be scheduled weekly. For the antenatal diagnosis of TAPS, the combination of MCA‐PSV ≥ 1.5 MoM in the anemic twin and ≤ 0.8 MoM in the polycythemic twin was agreed. Alternatively, MCA‐PSV discordance ≥ 1 MoM can be used to diagnose TAPS. Postnatally, hemoglobin difference ≥ 8 g/dL and intertwin reticulocyte ratio ≥ 1.7 were agreed criteria for diagnosis of TAPS. There was no agreement on the cut‐off of MCA‐PSV or its discordance for prenatal intervention. The panel agreed on prioritizing perinatal and long‐term survival outcomes in follow‐up studies. Conclusions Consensus‐based diagnostic features of TAPS, as well as cut‐off values for the parameters involved, were agreed upon by a panel of experts. Future studies are needed to validate these diagnostic features before they can be used in clinical trials of interventions. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Middle Cerebral Artery Doppler Velocimetry for the Diagnosis of Twin Anemia Polycythemia Sequence: A Systematic Review

“…The primary search of the Pubmed, Embase, and SCOPUS databases produced 432 publications. Based on abstract review, 54 of these publications were selected to be reviewed in their entirety [ 1 , 2 , 4 , 5 , 7 , 9 , 10 , 11 , 12 , 16 , 19 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 ]. The secondary search of bibliographies produced three additional publications which were also reviewed in their entirety for a total 57 publications [ 6 , 66 , 67 ].…”

“…Definitive diagnosis is obtained by comparing twin serum hemoglobin (Hb) levels with or without reticulocyte count ratios either postnatally or by intrauterine umbilical cord blood sampling. Treatment modalities vary by gestational age (GA) and include expectant management, fetoscopic laser surgery, intrauterine transfusion (IUT) with or without partial exchange transfusion (PET), selective reduction and preterm delivery [ 11 , 12 ].…”

Performance of Antenatal Diagnostic Criteria of Twin-Anemia-Polycythemia Sequence

“…Similarly, the ΔPSV >0.373 MoM criteria had an increased sensitivity of 93.3%, a specificity of 95.7%, and a 70% and 99.3% PPV and NPV [ 15 ]. The Delphi consensus thereby incorporated criteria that consisted of both a PSV MoM cut-off, as well as discordance, due to the findings that discordance may be of more significance than cut-off values alone, but further research is required to validate the optimum discordance used for diagnosis [ 13 , 16 ].…”

“…A recent consensus using the Delphi procedure has focused on alleviating heterogeneity and achieving a uniform diagnostic criteria for TAPS. This has proposed that a cut-off of >1.5 MoM in the donor and <0.8 MoM in the recipient, or a PSV delta of >1.0 MoM, is most appropriate for the antenatal diagnosis of TAPS [ 16 ].…”

Twin Anemia-Polycythemia Sequence (Zwillings-Anämie-Polyzythämie-Sequenz)

“…Im Gegensatz dazu weist der Empfängerzwilling eine Vmax in der ACM < 1,0 MoM auf. Einige Autoren präferieren 0,8 MoM als Grenzwert [5]. Als Referenzkurven können die von Klaritsch und Mitarbeiter erstellten Normwerte bei monochorialen Gemini verwendet werden [6].…”