OP08.01: Perinatal outcomes of early Twin–twin transfusion syndrome treated with laser: an international multicentre study

to report on perinatal outcomes of MCDA twin pregnancies complicated by early Twin–twin transfusion syndrome (TTTS) treated with laser surgery. This was an international multicentre cohort study. Monoamniotic twins, triplets or higher order multiples and fetuses with chromosomal/structural anomalies were excluded. Perinatal outcomes included survival up to 28 days, miscarriage, intrauterine demise, neonatal death and termination of pregnancy. 542 MCDA pregnancies were diagnosed with early TTTS at median 17 (IQR 16.6-17.6) weeks and treated with laser. Of these, 66 (12.2%) women were diagnosed ≤ 16 weeks. Table 1 reports on perinatal outcomes of these women according to Quintero Stage at diagnosis, in women diagnosed ≤ 16 weeks and in women with laser performed ≤ 18 weeks. Most (85.4%, n = 463) of the cases presented at stage II or III and 81.5% (n = 442) were treated with laser ≤ 18 weeks. In the whole cohort, 43.6%, 23.8% and 20.8% of pregnancies had two, one and no surviving fetuses, respectively. Laser surgery, even when performed ≤ 18 weeks, was associated with a good outcome with at least one surviving fetus in 67.4% and two surviving fetuses in 43.6% of pregnancies. 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.