JBRA Assisted Reproduction 2025;29(Suppl.2 SBRA 2025):255
Poster Presentation
29^th Annual Congress of the SBRA. São Paulo/SP - Brazil, 2025
doi: 10.5935/1518-0557.20263826

P-243. Waste your time, but do not discard: poor-quality blastocysts also implant

Bruna Campos Galgaro¹, Luiza da Silva Rodrigues¹, Julia Janis Santos¹, João Sabino Lahorgue da Cunha Filho¹

¹ INSEMINE - Rio Grande do Sul - Brasil

Objective: The aim of this study was to evaluate the pregnancy rate of poor-quality blastocysts in thawed single embryo transfer cycles.
Methods: This retrospective study included thawed single blastocyst transfer cycles from July 2023 to July 2025 at one fertility centre. The pregnancy rate was compared between good-quality and poor-quality blastocyst transfers, as classified by Gardner. A good-quality blastocyst was defined by grade 3 to 5 AA, AB, BA, or BB. Poor-quality counterparts were defined as embryos with a C classification for either trophectoderm or inner cell mass or expansion grade <3. Both day 5 and day 6 blastocysts were included, and cycles with preimplantational genetic test for aneuploidy were excluded from analysis. Female age, AMH (ng/mL), and BMI were assessed. Implantation was evaluated by the β-hCG test result 12 days after transfer. Data were analyzed using JASP software, and statistical analysis was performed using paired tests and logistic regression. Values were expressed as mean±SD, and significance was considered when p<0.05.
Results: In total, 109 good-quality and 56 poor-quality blastocyst transfers were analysed. The mean age, AMH, and BMI were 34.53±4.17, 4.11±3.29, and 26.21±5.65, respectively. The overall pregnancy rate of thawed single blastocyst transfer was 50.91%. As expected, the pregnancy rate was significantly higher in the good-quality embryos compared with the poor-quality blastocysts (61.47% vs 30.58%; p<0.001). As expected, the mean age of patients with β-hCG positive test results was lower (33.83±3.95 vs 35.26±4.29) than that of patients with no embryo implantation, whereas the AMH was higher (4.67±3.72 vs 3.51±2.66), p<0.05. Moreover, AMH (p=0.005), but not female age (p=0.068), was associated with blastocyst quality. BMI was not significantly different for blastocyst quality or implantation (p>0.05).
Conclusion: Although the pregnancy rate was significantly decreased, poor-quality blastocysts can lead to pregnancy in 30% of single blastocyst transfers. The commonly used term "non-usable" blastocysts, which are routinely discarded by many clinics, sometimes are the only viable embryos available from a patient. Therefore, poor-quality blastocysts should be carefully assessed and considered for transfer.