Consensus update on twin-twin transfusion syndrome staging: An international Delphi study
Bettina Paek1, Martin Walker1, Liesbeth Lewi2
1The Fetal Care and Treatment Center Seattle Children's Hospital Seattle Washington USA.
Introduction:
Twin-twin transfusion syndrome (TTTS) affects approximately 15% of monochorionic pregnancies and results in poor outcomes without treatment. The Quintero staging system has been used to characterize the severity of the syndrome and has been widely adopted due to its simplicity. However, it has been interpreted to indicate a chronological and synchronous evolution of TTTS disease that has been increasingly called into question. We sought to update the current staging system for TTTS to reflect current understanding of the underlying pathophysiology and to optimize guidance for clinical decision making and future research.
Methods:
A four-round Delphi procedure was conducted among an international panel of experts on TTTS to obtain consensus on an updated staging system. A core group of experts chosen based on their scholarship, international reputation, and medical specialty provided input on fact statements for the first two rounds. A larger group of experts was included in Rounds 3 and 4 and participation in round 4 was not contingent on participation in round 3. Consensus was defined as agreement of ≥ 70%.
Results:
A total of 462 experts from three continents were approached during the four rounds. The core group consisted of 16 experts, of which 15 (93.8%) completed all rounds. An additional 79 experts participated in round 3 (total of 94, response rate 20.3%) and an additional 18 experts participated in round 4 (total of 112, response rate 24.2%).Four areas of proposed changes were identified: (1) identification of a subgroup of monochorionic pregnancies at increased risk for progression to TTTS ("pre-TTTS"), (2) differentiation between donor and recipient disease for stages III and IV, (3) modifications to critically abnormal fetal cardiovascular findings defining stage III TTTS, and (4) recognition that TTTS with evidence of severe cardiac compromise can present without a fluid discordance satisfying classic criteria for stage I ("atypical TTTS").
Conclusion:
The updated consensus-based staging system for TTTS aims to improve clinical care by allowing earlier and more specific identification of disease, standardizing follow-up, and facilitating more robust research into TTTS's natural history, management, and outcomes. Prospective validation is warranted to assess its clinical utility.
