EP14.20: Current experience with laser therapy for Twin–twin transfusion syndrome treatment in university and public hospitals in Chile

The aim of this study was to analyse perinatal outcomes and complications associated with laser fetoscopy in two Chilean centres. Maternal, obstetric, and perinatal outcomes and complications of 144 laser therapy performed in Twin–twin transfusion syndrome (TTTS) at the University of Chile Hospital and San Borja Arriaran Hospital were analysed between December 2008 and June 2023. The median gestational age at the procedure was 20+2 weeks (range 16+1-26+6), with 55.4% classified as Stage III/IV. Selective fetal growth restriction (sFGR) was present in 51.6%, with 62.5% being type 2 and 3. Overall, survival at one month of life for the 141 cases with TTTS treated with laser therapy was 63.1% (178/282 fetuses). The survival of both twins was 45.4% (64/141 pregnancies), with both deaths occurring in 19.1% of pregnancies (27/141). Survival of at least one twin at one month of age was 80.9% (114/141). Overall survival was higher in TTTS with Quintero Stage II compared to stages III or IV (67.7% vs. 59.5%). The presence of sFGR did not significantly affect overall survival rates after laser therapy. Complications included premature rupture of membranes in 29.0% (41/141), with nine occurring within three weeks post-laser, polycythemia anemia sequence in 4.9% (7/141), intra-amniotic bleeding in 4.9% (7/141), chorioamnionitis within three weeks post-laser in 2.1% (3/141) progressing to septic shock in one case requiring ICU hospitalization, two cases requiring exploratory laparotomy for hemoperitoneum, and one case of amniotic band syndrome due to rupture of the intertwin membrane. This study demonstrates that our team has reached the upper part of the learning curve for laser coagulation by fetoscopy in treating TTTS, achieving results similar to those described by international centres with high experience in fetal therapy. This validates both centres as references for such procedures.