283 : Fertilization Rate and Embryonic Morphokinetic Parameters According to the Spindle Pattern in the Oocyte in Patients Over 40 Years of Age Who Underwent Polscope-Based ICSI

Background and Aims: The spindle is an essential cellular organelle that plays an important role in the oocyte during chromosome alignment and separation at meiosis. To examine the effect of presence or location of spindle on the fertilization rate and the morphokinetic parameter of embryo in patients over 40 years. Methods: This was a retrospective study based on data collected between January and December 2022. A total of 394 matured oocytes retrieved from 155 patients over 40 years undergoing ICSI cycles were imaged for meiotic spindle using PolScope. Oocytes were subdivided into two groups. Group A: oocytes had the spindle forming 0 to 15 ∘ angles, group B: oocytes had the spindle forming 15 ∘ or more. Morphokinetic analysis; Embryoscope+ using guided semi-automatic annotation. Results: Meiotic spindles were visualized in 369 oocytes (93.65%, 369/394) and were not visualized in 25 oocytes (6.35%, 25/394). The fertilization rate (73.98% and 44.00%; P=0.0012) and good quality embryo rate (41.39% and 27.27%; P=0.365) were significantly higher in oocyte with spindle, compared with in oocyte without spindle. Divided by spindle angle, group A was significantly higher fertilization rate, good quality rate compared to group B. There was no signicant difference in KID3 score (mean, 3.91±1.46 and 4.00±1.22; P=0.39) and the D3 morphokinerics parameter among the different groups. However, the D5 morphokinetics parameter (tSC; 81.56±7.48 vs 85.73±8.29, tM; 87.22±7.89 vs 94.00±11.60, tSB; 96.05±8.03 vs 102.18±9.15, tB; 106.39±10.04 vs 113.06±10.88, P