| Popis: |
OBJECTIVE: A published algorithm based on kinetic markers classifies embryos from A to E according to implantation potential (1). The objective of this study is to evaluate if the source of oocytes (fresh or vitrified) has an impact on the percentage of embryos falling within each category. DESIGN: Retrospective cohort study. MATERIALSANDMETHODS: Oocytes frommixed Intra Citoplasmatic Sperm Injection cycles (fresh + vitrified oocytes) were monitored in a timelapse system (N1⁄4 658; 387 fresh and 271 vitrified). Variables studied included: exact timing to 2 (t2), 3 (t3), 4 (t4), and 5 cell (t5). We also evaluated cell division intervals such as cc2 1⁄4 t3-t2 and s21⁄4t4-t3. To evaluate embryo quality based in morphokinetics, the proportion of optimal embryos was determined from our previous observations, identifying embryos in a best time range with a higher implantation potential. The proposed optimal timings were as follows: t51⁄4 48.8-56.6 hours, cc21⁄4 < 12 hours and s2< 0.75 hours. To further evaluate correlation between morphokinetic parameters and the type of the oocyte (fresh or vitrified), we developed a hierarchical classification: t5 (if 48.8%t5%56.6 hr then grade A or B, otherwise grade C or D) and secondary variable: s2 (if s2%0.75 hr then grade A or C, otherwise B or D) divides the remaining embryos into grades A, B, C or D in order of decreasing implantation rate.With cc2, we obtained a plus/minus division in each of the previous mentioned categories.We applied a Chi-squared for comparison of percentages with p |
