Dados do Trabalho

Title

Do time-lapse incubator systems improve results in embryo development?

Objective

Evaluate the fertilization, embryo quality, blastulation, and ploidy rates of embryos cultivated in k-systems benchtop incubators (KS) versus embryoscope (ES) time-lapse systems.

Methods

A retrospective study was conducted, including 152 cycles of ICSI + PGTa from January to May 2023. Among them, 116 patients underwent embryo culture in k-systems incubators, and 36 patients were cultivated in embryoscope incubators. A total of 996 zygotes were evaluated, with patients distributed into three groups based on age: Group 1 - patients up to 35 years old, with 23 patients in KS and 9 in ES. Group 2 - patients aged 36 to 39 years, with 46 patients in KS and 10 patients in ES. Group 3 - patients aged 40 or older, with 47 patients in KS and 17 patients in ES. The same protocol and unique culture medium were used for both incubators. The following variables were assessed: total fertilization rate; 2PN fertilization; top-quality embryos on days 3, 5, and 6; blastulation; and results of embryo genetic analysis (PGT-a). All cycles were subjected to extended culture, and embryo biopsy was performed on the 5th or 6th day of development. Preimplantation genetic testing (PGT-a) was performed using next-generation sequencing (NGS), and embryos were categorized as euploid or aneuploid. Statistical analysis was performed using Pearson's chi-square test or Fisher's exact test, considering a p-value <0.05.

Results

Out of 996 zygotes, 705 were cultured in KS incubators and 487 evolved to blastocyst stage (69.0%); in ES incubators, 291 zygotes were cultured, with 202 reaching blastocyst stage (69.0%). When splited by age, the results were as follows: Group 1: In KS, 177 zygotes and 132 blastocysts were formed (75%); in ES, 84 zygotes and 63 blastocysts (75%). Group 2: In KS, 308 zygotes and 229 blastocysts (74%); in ES, 64 zygotes and 54 blastocysts (84%). Group 3: In KS, 220 zygotes and 126 blastocysts (57%); in ES, 143 zygotes and 79 blastocysts (55%). Regarding the rates of total fertilization and top-quality embryos (D3/D5/D6), there was no statistical difference between the groups. However, in the evaluation of the 2PN fertilization rate, there was a statistical difference (p = 0.024) in Group 3, with ES showing a higher rate compared to KS (78% and 69%, respectively). Also, in the blastulation analysis, there was a statistical difference in Group 2 (p = 0.040), with ES outperforming KS (79% and 67%, respectively). In the comparison between groups about genetic analysis, the evaluated parameters did not show significant statistical differences.

Conclusion

The results obtained from this study support the understanding that embryo culture in embryoscope time-lapse systems is equivalent and, in some aspects, even superior to those obtained in benchtop incubators.

Keywords

Time-lapse systems, benchtop incubators, blastocyst, euploid.