Effect of the 'Ready-to-Use Vitrification and Warming Kit' on Pregnancy Rates Following Vitrification-warmed Blastocyst Transfer: A Retrospective Study.
- 1Takeuchi Ladies Clinic/Center for Reproductive Medicine, Kagoshima-shi, Kagoshima, Japan.
- 2Takeuchi Ladies Clinic/ART Kagoshima Branch, Kagoshima-shi, Kagoshima, Japan.
Abstract
Background
A newly developed ready-to-use (RtU) vitrification-warming kit enables vitrification in 12-13 min and thawing in 6 min, thereby simplifying culture operations by reducing overall handling time, but its effects on operability and clinical pregnancy rates following frozen-thawed embryo transfer need to be assessed.Aim
This study aimed to compare clinical pregnancy rates between RtU kit and conventional CryoTip method used for vitrification in women undergoing single blastocyst frozen embryo transfer.Settings and design
A retrospective cohort study performed in a random sample of patients who underwent frozen embryo transfer between October 2023 and December 2024.Materials and methods
Blastocyst vitrification was performed using the CryoTip and RtU kit. Only single blastocyst transfers during a cycle of hormone replacement therapy were performed.Statistical analysis used
Kruskal-Wallis and Chi-squared tests were used with continuity correction.Results
The RtU kit demonstrated a higher warming rate than the CryoTip system while maintaining comparable cooling characteristics. No significant differences were observed between groups in pregnancy positivity (68.2 vs. 71.6%), clinical pregnancy (56.2 vs. 65.5%) and miscarriage rates (11.5 vs. 13.9%). Higher live birth rates were observed in the RtU group (54.1% vs. 42.4%).Conclusions
The RtU vitrification-warming kit shortened the warming procedure and showed higher live birth rates compared with the CryoTip method. However, the favourable association with live birth did not remain statistically significant after adjustment for confounding factors. Further prospective studies are warranted.
Related
- Case Report: Monochorionic triamniotic triplet pregnancy following single vitrified-warmed blastocyst transfer
- Sequential blastocyst transfer improved pregnancy outcomes in patients undergoing frozen-thawed embryo transfer cycles: who will be the ultimate beneficiary
- Trigger-day progesterone-to-mature-oocyte ratio, cycle-level blastocyst yield, and recorded embryo-transfer outcomes: a retrospective cohort study
- Genetic and non-genetic contributions to early spontaneous miscarriage in women with PCOS undergoing PGT-A and single euploid blastocyst transfer: a retrospective cohort study
- Predicting blastocyst viability: the role of post-vitrification re-expansion speed and its correlation with artificial collapse and preimplantation genetic testing.
BibTeX
@article{mizobe2026effect,
title = {{Effect of the 'Ready-to-Use Vitrification and Warming Kit' on Pregnancy Rates Following Vitrification-warmed Blastocyst Transfer: A Retrospective Study.}},
author = {Yamato Mizobe and Yuji Orita and Kazuhiro Takeuchi},
journal = {Journal of human reproductive sciences},
year = {2026},
month = jul,
doi = {10.4103/jhrs.jhrs_49_26},
url = {https://europepmc.org/article/MED/42924380},
note = {CC BY-NC-SA},
}
RIS
TY - JOUR
TI - Effect of the 'Ready-to-Use Vitrification and Warming Kit' on Pregnancy Rates Following Vitrification-warmed Blastocyst Transfer: A Retrospective Study.
AU - Yamato Mizobe
AU - Yuji Orita
AU - Kazuhiro Takeuchi
PY - 2026
DA - 2026/07/01
JO - Journal of human reproductive sciences
DO - 10.4103/jhrs.jhrs_49_26
UR - https://europepmc.org/article/MED/42924380
AB - Background A newly developed ready-to-use (RtU) vitrification-warming kit enables vitrification in 12-13 min and thawing in 6 min, thereby simplifying culture operations by reducing overall handling time, but its effects on operability and clinical pregnancy rates following frozen-thawed embryo transfer need to be assessed.Aim This study aimed to compare clinical pregnancy rates between RtU kit and conventional CryoTip method used for vitrification in women undergoing single blastocyst frozen embryo transfer.Settings and design A retrospective cohort study performed in a random sample of patients who underwent frozen embryo transfer between October 2023 and December 2024.Materials and methods Blastocyst vitrification was performed using the CryoTip and RtU kit. Only single blastocyst transfers during a cycle of hormone replacement therapy were performed.Statistical analysis used Kruskal-Wallis and Chi-squared tests were used with continuity correction.Results The RtU kit demonstrated a higher warming rate than the CryoTip system while maintaining comparable cooling characteristics. No significant differences were observed between groups in pregnancy positivity (68.2 vs. 71.6%), clinical pregnancy (56.2 vs. 65.5%) and miscarriage rates (11.5 vs. 13.9%). Higher live birth rates were observed in the RtU group (54.1% vs. 42.4%).Conclusions The RtU vitrification-warming kit shortened the warming procedure and showed higher live birth rates compared with the CryoTip method. However, the favourable association with live birth did not remain statistically significant after adjustment for confounding factors. Further prospective studies are warranted.
SN - 0974-1208
SN - 1998-4766
ER -