JBRA Assisted Reproduction 2025;29(Suppl.2 SBRA 2025):169
Poster Presentation
29^th Annual Congress of the SBRA. São Paulo/SP - Brazil, 2025
doi: 10.5935/1518-0557.20263919

P-157. Maternal Age, Not Infertility Type, Shapes Blastocyst Morphological Integrity

Ellayne Cavalcanti Queiroz¹, Eduardo Gomes Sá¹, Andrea Mesquita Lima¹, Gleicyane Sousa Santos Alam¹, Renata Reis Pimentel Castro, Hamilton de Martin¹, Tulius Augustus Ferreira Freitas¹, Marcus Aurélio Paiva Bessa¹, Eduardo Paula Miranda¹, Sebastião Evangelista Torquato¹

¹ Bios Centro de Medicina Reprodutiva – Fortaleza -CE - Brasil

Objective: To evaluate whether infertility diagnosis and maternal age influence blastocyst fragmentation patterns classified by the Blastocyst Fragmentation Indicator (BFI). This study represents a focused segment of a larger, ongoing investigation.
Methods: This retrospective cohort included 1,182 blastocysts individually cultured in time-lapse incubators between September 2022 and December 2024. Embryos were classified into three BFI categories: NN (no fragmentation), FN (fragmentation of the inner cell mass), and FF (fragmentation of both the inner cell mass and trophectoderm). Infertility diagnosis was categorized into male factor, female anatomic factor, endometriosis, ovarian insufficiency, and unexplained infertility. Maternal age was grouped as <37 years (group 1) or ≥37 years (group 2). Associations between BFI classification, infertility diagnosis, and maternal age were assessed using chi-squared tests and multinomial generalized linear models (GLM). Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to quantify risk differences, and estimated marginal means were used to illustrate predicted probabilities for each BFI category.
Results: No significant association was observed between infertility diagnosis and BFI distribution (χ²=5.72, degrees of freedom=8, p=0.679), and GLM analysis confirmed the absence of predictive value (p=0.695; R²=0.0026). Across all infertility groups, the distribution of blastocysts remained stable, with approximately 63.1% categorized as NN, 19.8% as FN, and 17.1% as FF. Rates of fragmentation were similar between male factor (61.7% NN, 21.8% FN, 16.5% FF) and unexplained infertility cases (65.4% NN, 18.7% FN, 15.9% FF), with no significant variation across etiologies. In contrast, maternal age had a significant effect on fragmentation patterns. Patients <37 years exhibited a higher proportion of non-fragmented embryos (70.3% NN) compared to those ≥37 years (57.1% NN). Fragmentation increased with age: FN rose from 16.9% to 22.2%, and FF from 12.8% to 20.7%. Chi-square analysis confirmed this association (χ²=23.1, df=2, p<0.001), and GLM reinforced the strength and directionality of the effect (p<0.001; R²=0.0108). Maternal age ≥37 years was associated with higher odds of FN (OR=1.99; 95% CI: 1.44–2.75; p < 0.001) and FF (OR=1.62; 95% CI: 1.20–2.19; p=0.002) compared to NN. Marginal means analysis further illustrated the shift in fragmentation patterns with aging, indicating a progressive decline in blastocyst morphodynamics.
Conclusion: The Blastocyst Fragmentation Indicator (BFI) is independent of infertility etiology, maintaining consistent distribution across diverse diagnostic groups. In contrast, maternal age ≥37 years significantly increases fragmentation involving both the inner cell mass and the trophectoderm. These findings emphasize that blastocyst fragmentation is more closely related to intrinsic oocyte competence than to the underlying cause of infertility. The BFI thus emerges as a promising dynamic morphology-based parameter for embryo selection, with clinical relevance enhanced when interpreted alongside maternal age. This study contributes to a broader investigation into dynamic embryo viability assessment using time-lapse imaging.