P-124 Behavior of the second polar body and its relationship to subsequent human embryonic development

Abstract Study question Is the behavior of second polar body (PBII) associated with subsequent human embryonic development? Summary answer Human zygotes morphologically static PBII showed significantly higher rates good quality embryos and utilization than showing various behaviors. What is known already In recent years, time-lapse incubators have become widely available, enabling continuous observation embryos. With imaging, bodies that exhibit a variety behaviors can be observed from time extrusion to first cleavage. Although ploidy morphology been variously reported reflect after fertilization, there are few studies on body, which thought directly state oocyte sperm entry, its relationship development. design, size, duration This retrospective study involving imaging 285 normally fertilized ICSI between January August 2019. Of those, 262 suitable images cleavage were examined. Zygotes during classified into Group 1 (n = 68), moving-like-amoeba, shrinking, fragmenting, and/or ruffling 2 194). Participants/materials, setting, methods included 64 cycles ART treatment. Gonadotrophin-releasing hormone analogues (GnRHa) gonadotrophins used for ovarian stimulation prior retrieval. Time-lapse was performed in EmbryoScope®. The irregular divisions at cleavage, early stage based modified Veeck’s criteria, blastocysts (≥4BB) Gardner grading system cryopreservation embryo transfer compared groups. Main results role chance proportion (morphologically PBII) (PBII behaviors) 26.0% 68/262) 74.0% 194/262). mean maternal age (years) 34.8 ± 5.4 35.0 4.8 2. incidence (direct/reverse) 22.1% 28.9% Good cryopreserved/transferred Day-2/3 according our clinic policy, only those not cryopreserved or freshly transferred extendedly cultured up Day-7. rate 30.6% 11/36) 23.3% 30/129) Thus, no significant differences blastocysts. Meanwhile, [P<0.01; 57.4% 39/68) 1, 37.1% 72/194) 2]. also [P<0.05; 64.7% 44/68) 49.5% 96/194) Limitations, reasons caution an observational using zygotes. Since number blastocyst limited fair poor stage. Wider implications findings revealed suggests may new indicator evaluation. Trial registration applicable