P-110 Effects of embryo culture under atmospheric oxygen concentration on cumulative live birth rate and birth weight

Abstract Study question The purpose of this study is to compare cumulative live birth rate and perinatal outcomes embryos cultured in 20% oxygen 5% oxygen. Summary answer Atmospheric concentration not only affects the quality embryos, but also weight after embryo transfer. What known already Whether culture can effectively improve outcome embryonic pregnancy still controversial. There a lack scientific data support from large sample, especially regarding as primary outcome. design, size, duration This retrospective included patients who received vitro fertilization (IVF) treatment with their own first oocyte retrieval cycles 1 January 2016 through 31 November 2019, transfer dates limited 2020. Our final analytic cohort 31,566 women. Participants/materials, setting, methods Embryos were at or until third day for transplantation freezing. If prolonged was required, both groups transferred incubator blastocyst stage Other laboratory clinical procedures consistent between two groups. Main results role chance high-quality group significantly higher than that （0.51 ± 0.33 vs 0.49 0.33; β = −0.03; 95%CI, −0.03–−0.02; P < 0.001), while slow-developing lower （0.52 0.31 0.56 0.31; 0.04; 0.03–0.05; 0.001). (62.4% 58.6%; adjusted OR 0.85; 0.81-0.90). Z score （birthweight corrected gestational age birth, gender parity (birth weight: 3.28 0.48 3.30 0.50, 0.022, 0.004-0.04; score: 0.22 1.01 0.26 1.04, 0.037, 0.001–0.074). No matter what group, rate, good those proportion no transferable group. Limitations, reasons caution Limitations include oocytes on (D0), randomly distributed incubators different concentrations 1. Because it study, grouping randomized. Wider implications findings We counted largest sample present, took main indicator, tracked outcome, using reliable prove atmospheric has serious long-term irreversible effects development. Trial registration number applicable