Predicting blastocyst viability: the role of post-vitrification re-expansion speed and its correlation with artificial collapse and preimplantation genetic testing.
7 affiliations
- 1Department of Obstetrics and Gynecology, Infertility and IVF Institute, Sheba Medical Center, Ramat Gan, Israel. [email protected].
- 2Gray Faculty of Medical and Health Sciences, Tel Aviv University, Tel Aviv, Israel. [email protected].
- 3Arrow Program for Medical Research Education, Sheba Medical Center, Ramat Gan, Israel. [email protected].
- 4Arrow Program for Medical Research Education, Sheba Medical Center, Ramat Gan, Israel.
- 5The Adelson School of Medicine, Ariel University, Ariel, Israel.
- 6Department of Obstetrics and Gynecology, Infertility and IVF Institute, Sheba Medical Center, Ramat Gan, Israel.
- 7Gray Faculty of Medical and Health Sciences, Tel Aviv University, Tel Aviv, Israel.
Abstract
Background
Post-thaw blastocyst behavior is clinically relevant and closely linked to implantation and pregnancy success after frozen embryo transfer. Re-expansion of the blastocyst after warming is recognized as an important indicator of embryo viability and has been associated with clinical outcomes, although it is not routinely evaluated in a dynamic manner. In addition, blastocysts undergo different laboratory procedures before vitrification, such as trophectoderm biopsy for genetic testing and artificial collapse, which may influence post-thaw re-expansion dynamics. Therefore, this study aimed to dynamically assess post-thaw blastocyst re-expansion and to evaluate its association with pregnancy outcomes, as well as to examine differences in re-expansion dynamics across different laboratory procedures.Results
A total of 463 frozen embryo transfer cycles were analyzed, including 170 cycles selected for detailed morphokinetic evaluation. Blastocysts were categorized according to pre-vitrification procedures into a Control group, a biopsy group, and an artificial collapse group. After thawing, the initial re-expansion ratio (T1) was slightly lower in the artificial collapse group compared with the Control and biopsy groups, although this difference was not statistically significant (p = 0.096). The artificial collapse group demonstrated a significantly higher maximal re-expansion ratio (p = 0.031) and a longer time to reach this maximum (p = 0.015). Re-expansion speed was highest in the artificial collapse group, followed by the biopsy group and the Control group, and showed a strong positive correlation with pregnancy outcomes (p = 0.011). Blastocysts in the highest Average Re-expansion Speed Rate (ARSR) quartile (≥ 5.1%) were more than three times more likely to result in pregnancy compared with those in the lowest quartile. The highest ongoing pregnancy rate was observed in the artificial collapse group (52.6%), followed by the biopsy group (41.7%) and the Control group (35.9%) (p = 0.033).Conclusion
A dynamic assessment of post-thaw blastocyst re-expansion is strongly associated with pregnancy outcomes after frozen embryo transfer. Differences in re-expansion dynamics were observed between blastocysts subjected to different laboratory procedures, with artificial collapse before vitrification showing the most favorable profile. This approach may provide a useful tool for improving embryo evaluation and supporting clinical decision-making in IVF.
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BibTeX
@article{aizer2026predicting,
title = {{Predicting blastocyst viability: the role of post-vitrification re-expansion speed and its correlation with artificial collapse and preimplantation genetic testing.}},
author = {Adva Aizer and Shay Kaplan and Meirav Noach-Hirsh and Olga Dratviman-Storobinsky and Roni Hoshen and Aliza Segev-Zahav and Jigal Haas and Raoul Orvieto},
journal = {Journal of ovarian research},
year = {2026},
month = jul,
doi = {10.1186/s13048-026-02199-3},
url = {https://europepmc.org/article/MED/42928227},
note = {CC BY-NC-ND},
}
RIS
TY - JOUR
TI - Predicting blastocyst viability: the role of post-vitrification re-expansion speed and its correlation with artificial collapse and preimplantation genetic testing.
AU - Adva Aizer
AU - Shay Kaplan
AU - Meirav Noach-Hirsh
AU - Olga Dratviman-Storobinsky
AU - Roni Hoshen
AU - Aliza Segev-Zahav
AU - Jigal Haas
AU - Raoul Orvieto
PY - 2026
DA - 2026/07/28
JO - Journal of ovarian research
DO - 10.1186/s13048-026-02199-3
UR - https://europepmc.org/article/MED/42928227
AB - Background Post-thaw blastocyst behavior is clinically relevant and closely linked to implantation and pregnancy success after frozen embryo transfer. Re-expansion of the blastocyst after warming is recognized as an important indicator of embryo viability and has been associated with clinical outcomes, although it is not routinely evaluated in a dynamic manner. In addition, blastocysts undergo different laboratory procedures before vitrification, such as trophectoderm biopsy for genetic testing and artificial collapse, which may influence post-thaw re-expansion dynamics. Therefore, this study aimed to dynamically assess post-thaw blastocyst re-expansion and to evaluate its association with pregnancy outcomes, as well as to examine differences in re-expansion dynamics across different laboratory procedures.Results A total of 463 frozen embryo transfer cycles were analyzed, including 170 cycles selected for detailed morphokinetic evaluation. Blastocysts were categorized according to pre-vitrification procedures into a Control group, a biopsy group, and an artificial collapse group. After thawing, the initial re-expansion ratio (T1) was slightly lower in the artificial collapse group compared with the Control and biopsy groups, although this difference was not statistically significant (p = 0.096). The artificial collapse group demonstrated a significantly higher maximal re-expansion ratio (p = 0.031) and a longer time to reach this maximum (p = 0.015). Re-expansion speed was highest in the artificial collapse group, followed by the biopsy group and the Control group, and showed a strong positive correlation with pregnancy outcomes (p = 0.011). Blastocysts in the highest Average Re-expansion Speed Rate (ARSR) quartile (≥ 5.1%) were more than three times more likely to result in pregnancy compared with those in the lowest quartile. The highest ongoing pregnancy rate was observed in the artificial collapse group (52.6%), followed by the biopsy group (41.7%) and the Control group (35.9%) (p = 0.033).Conclusion A dynamic assessment of post-thaw blastocyst re-expansion is strongly associated with pregnancy outcomes after frozen embryo transfer. Differences in re-expansion dynamics were observed between blastocysts subjected to different laboratory procedures, with artificial collapse before vitrification showing the most favorable profile. This approach may provide a useful tool for improving embryo evaluation and supporting clinical decision-making in IVF.
SN - 1757-2215
ER -