Percent Absent End-Diastolic Velocity and Risk of Donor Twin Demise in Twin-Twin Transfusion Syndrome [19A

Abstract

INTRODUCTION: We examined the association of percent absent end-diastolic velocity (%AEDV) in the umbilical artery with intrauterine fetal demise (IUFD) of the donor twin after laser surgery in patients with twin-twin transfusion syndrome (TTTS) Quintero stages III/IV. %AEDV was calculated as 100x the proportion of total cardiac cycle spent in AEDV. METHODS: Retrospective study of TTTS stage III/IV patients between 2006 and 2016. Donors were classified as having persistent AEDV (yes/no). In Part 1, we used multiple logistic regression analysis to test whether AEDV was associated with donor IUFD. We stratified these analyses by estimated fetal weight (EFW) discordance of ≥20% or <20%. In Part 2, we used similar models to test only those with AEDV to determine whether %AEDV was associated with IUFD. This was an IRB approved study. RESULTS: Of 344 stage III/IV TTTS cases, 153 (44.5%) donors had preoperative AEDV. In Part 1, we did not confirm an independent association between AEDV and donor IUFD. In Part 2, patients with AEDV who were discordant (N=129), had the following characteristics associated with donor IUFD: %AEDV (OR 1.04, 95% CI 1.01-1.08), %EFW discordance (OR 1.07, 95% CI 1.02-1.13), and presence of arterioarterial anastomoses (OR 5.15, 95% CI 2.06-12.89). In the non-discordant group (N=24), no association was found between %AEDV and donor IUFD. CONCLUSION: The presence of preoperative persistent AEDV was not an independent risk factor for donor IUFD in stage III/IV TTTS patients undergoing laser surgery. However, among donors with preoperative AEDV and EFW discordance ≥20%, %AEDV was positively associated with donor IUFD.