P-283 Is it time to abandon the practice of double embryo transfer?

Abstract Study question Can single embryo transfer (SET) with euploid embryos be an effective strategy for improving livebirth rate (LBR) and reducing multiple pregnancy (MPR)? Summary answer SET of leads to higher LBR lower MPR per cycle compared DET untested in all age groups. What is known already Multiple pregnancy, IVF, advanced maternal are independently associated adverse obstetric outcomes their coexistence likely lead aggravation risks. often recommended women aged over 37 the aim but at cost significantly MPR. Preimplantation genetic testing aneuploidy (PGT-A) was pioneered select transfer. We evaluate whether utilization PGTa a subsequent can achieving embryos. design, size, duration This retrospective national cohort study using data from UK Human Fertilisation Embryology Authority (HFEA). analysed 137, 186 IVF treatment cycles performed between 2017-2018 UK. Other than grouping by age, no further confounders were controlled for. Both fresh frozen transfers included. Participants/materials, setting, methods included cycles. Cycles undertaken donation or storage excluded. Cycle parameters including ethnicity, number previous cycles, infertility history, outcomes, gestational delivery, birthweight early evaluated. following (PGTa SET) vs. Main results role chance utilised 1990 which 1521 had (76%, 95% CI 75-78%). Of 135, 195 not utilised, there 37, 281 (28%, 27-28%). There 319 (16%, 14-18%). In group, 16, 680 (12%, 12-13%). Per cycle, groups group (including those under 35) (43.7% 31.4%, p < 0.001 0.3% 8.4%, 0.0001, respectively). Limitations, reasons caution It unclear HFEA dataset includes intended collections when assessing thus we unable report on started. Wider implications findings Advanced increased perinatal risk morbidity. population particularly vulnerable pregnancy. followed Trial registration applicable