OP12.07: Consensus diagnostic criteria and management of twin anemia polycythaemia sequence: a Delphi procedure

Twin anemia polycythaemia sequence (TAPS) is associated with increased perinatal mortality and morbidity. Inconsistencies in the diagnostic criteria for TAPS hinders the ability to establish robust evidence-based management or monitoring. The main aim of this study was to determine, by expert consensus using a Delphi procedure, the key diagnostic features and preferred management of TAPS. A Delphi process was conducted among an international panel of twin-experts. Panel members were provided with a list of literature-based parameters for diagnosing, monitoring and management of TAPS. They were asked to rate their importance on a five-point Likert scale. Consensus was sought to determine the cut-off values of diagnostic parameters, as well as parameters used in the monitoring, management and assessment of outcome of twin pregnancy complicated by TAPS. A total of 50 experts completed the first round and 33 (66%) completed all three rounds. There was agreement that monitoring interval for the development of TAPS should be every two weeks, but no agreement on the gestation when to start. Once the diagnosis is made, monitoring should be scheduled weekly. For the diagnosis of TAPS, the combination of middle cerebral artery (MCA) peak systolic velocity (PSV) > 1.5MoM in the anemic twin and < 0.8MoM in the polycythemic twin was agreed. Alternatively, MCA PSV discordance > 1MoM. Postnatally, inter-twin reticulocyte ratio > 1.7 or hemoglobin difference > 8 g/dL were agreed. There was no agreement on the cut-off of the MCA PSV or its discordance for prenatal intervention, or on the first-line management option. The panel agreed on prioritising perinatal and long-term survival outcomes in the follow-up studies. 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. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.