Fertility & Reproduction (Dec 2023)
#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
Abstract
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[Formula: see text] angles, group B: oocytes had the spindle forming 15[Formula: see text] 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<0.05) showed a significant association with spindle location. Conclusions: Visible spindle or location close to polar body showed higher fertilization rate and good quality embryo as well as differed in morphokinetic parameters on day 5. This study confirmed a positive relationship between the spindle and fertilization rate. A significant difference of morphokinetics was found in day 5, but not in day 3.