JBRA Assist. Reprod. 2025;29(Suppl 1):48-48
POSTER PRESENTATION
doi: 10.5935/1518-0557.20250102
1Huntington Pró-Criar Medicina Reprodutiva - Belo Horizonte, MG, Brazil
2Huntington Medicina Reprodutiva - São Paulo, SP, Brazil
Objective: Maternal age is a key factor influencing reproductive outcomes, including embryo morphology and ploidy status. Timelapse imaging has enabled the assessment of additional embryo characteristics, such as morphokinetics. The KIDScore algorithm predicts an embryo’s implantation potential using morphokinetic parameters. This study aims to evaluate whether maternal age influences embryo morphokinetics and KIDScore assessments and how these parameters vary between euploid and aneuploid embryos based on morphology and Society for Assisted Reproductive Technology (SART) maternal age subgroups.
Methods: This retrospective cohort study included 891 biopsied blastocysts from 255 cycles involving 209 patients who underwent in vitro fertilization (IVF) with autologous fresh oocytes between January 2023 and December 2024 in a private fertility center. All embryos were culture in the EmbryoscopePlus® system (Vitrolife) and underwent preimplantation genetic testing for aneuploides. Blastocyst morphology was assessed using the Gardner criteria and classified into three subgroups based on inner cell mass and trophoectoderm quality: Excellent (AA graded), Good (A and B grades) and Poor (the presence of C grades). Maternal age was analyzed according to SART groups: Group 1 (G1) - <35, Group 2 (G2) - between 35 and 37, Group 3 (G3) - between 38 and 40, Group 4 (G4) - between 41 and 42 and Group 5 (G5) - >42 years. Statistical analysis was performed using Kruskal-Wallis, MannWhitney, Fisher’s exact, and Chi-square tests, with significance set at p<0.05.
Results: The distribution of biopsied embryos across SART subgroups was: G1: 14.0%, G2: 21.5%,G3: 36.0%, G4: 23.0% and G5: 5.4%. The mean number of embryos per cycle was 4.46, 4.0, 3.87, 2.73 and 2.29 for G1-G5, respectively. The number of oocytes retrieved and mature oocytes (MII) per cycle were significantly lower in G4 (8.0±4.5 and 6.1±3.6) and G5 (9.3±5,7 and 5.9±3.3) compared to G1 (15.5±9.1 and 11.3±7.5, p<0.0001). Fertilization, MII and blastulation rates were not significantly different across groups. The number of blastocyst was lower in G4 (2.8±1.6) and G5 (2.3±1.3) compared to G1 (5,3±3,3), G2 (4,3±2,5) and G3 (4,2±3,1, p<0.0001). The euploidy rate was higher in G1 and G2 (68.2%±25.9% and 49.3%±32.2%) compared to G3 (33.2%±28.1%), G4 (14.6%±26.4%) and G5 (13.5%±31.5%, p<0.0001). Euploidy rates in G3 were also significantly higher than G4 and G5 (p<0.0001). The proportion of Day 5 (D5) and Day 6 (D6) blastocyst was lower in G5 (58.3%/41.7%) compared to G1: 80.8%/17.6%, G2: 81.8%/18.2%, G3: 76.6%/19.6% and G4:73.7%/23.4%, p=0.0097. G5 had a lower proportion of Excellent (20.8%), Good (35.4%), and higher Poor (43.8%) morphology embryos compared to all other SART groups, p<0.0001 (G1: 46.4%/40%/13.6%, G2: 41.7%/43.2%/15.1%, G3: 37.7%/45.8%/16.5% and G4: 37.1%/43.4%/19.5% respectively).KIDScore was assessed only in D5 embryos, as the algorithm lacks accuracy for D6 blastocyst. The mean KIDScore was lower in G5 (6.6±1.6) compared to G1 (7.6±1.6, p=0.0084). No significant differences in KIDScore were observed in euploid or aneuploid embryos across SART groups (p=0.55 and 0.08, respectively). No significant differences were found in the proportion of Excellent, Good and Poor morphology D5 embryos among SART groups (p=0.051) or between euploid and aneuploidy D5 embryos across SART groups (p=0.55 and 0.21, respectively). However, a significant difference in KIDScore between euploid and aneuploid embryos was observed in G2 (7.5±1.3 vs. 6.8±1.4, p=0.0026) and G3 (7.8±1.3 vs. 7.1±1.5, p<0.0001).
Conclusion: Maternal age significantly impacts key reproductive parameters, including oocyte yield, blastocyst formation, euploidy rates, and embryo morphology. Older maternal age, particularly >42 years, is associated with lower blastocyst formation rates, poorer embryo morphology, and reduced KIDScore values in D5 embryos. However, KIDScore did not differ significantly between euploid and aneuploid embryos most age groups, except in G2 and G3. These findings provide insights into age-related reproductive decline and its impact on embryo selection criteria in IVF.