252: Impact of selective intrauterine growth restriction on laser therapy outcomes in twin twin transfusion syndrome

To determine if outcomes of fetoscopic laser photocoagulation in twin twin transfusion syndrome (TTTS) differ from TTTS with concomitant selective intrauterine growth restriction (sIUGR). Retrospective cohort study of all cases of TTTS treated in a single center between December 2014 and December 2018. Data was collected from maternal, obstetrical and neonatal chart review. Sixty patients were identified, 24 of them having concomitant sIUGR. One patient was lost to follow-up. Mean gestational age at diagnosis and at treatment was 19.59 and 20.11 for TTTS alone and 20.66 and 21.40 for concomitant sIUGR. Donor fetal death was more frequent in the concomitant sIUGR group. However, there was no difference in overall survival between groups when comparing concomitant type 2-3 sIUGR to concomitant type 1 and TTTS alone. A summary of our results is shown in the table below. After fetoscopic laser photocoagulation, overall twin survival does not differ between the two groups, which could be due to the small sample size. Donor fetal death and preterm labour are more common in the concomitant sIUGR group. Other fetal and obstetrical complications do not differ. To date, there is no published data on the impact of sIUGR on laser therapy outcomes in TTTS. Further study is warranted to help counsel patients facing this procedure.