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. 2024 Jun;41(6):1539-1547.
doi: 10.1007/s10815-024-03115-8. Epub 2024 Apr 20.

Effect of time post warming to embryo transfer on human blastocyst metabolism and pregnancy outcome

Goli Ardestani  1 , Marion Martins  2   3 , Olcay Ocali  2 , Tim H Sanchez  4 , Colwyn Gulliford  4 , C Brent Barrett  2 , Denny Sakkas  2
Affiliations

Effect of time post warming to embryo transfer on human blastocyst metabolism and pregnancy outcome

Goli Ardestani et al. J Assist Reprod Genet. 2024 Jun.

Abstract

Purpose: This study is aiming to test whether variation in post warming culture time impacts blastocyst metabolism or pregnancy outcome.

Methods: In this single center retrospective cohort study, outcomes of 11,520 single frozen embryo transfer (FET) cycles were analyzed from January 2015 to December 2020. Patient treatments included both natural and programmed cycles. Time categories were determined using the time between blastocyst warming and embryo transfer: 0 (0- <1h), 1 (1-<2h), 2 (2-<3h), 3(3-<4h), 4 (4-<5), 5 (5-<6), 6 (6-<7) and 7 (7-8h). Non-invasive metabolic imaging of discarded human blastocysts for up to 10h was also performed using Fluorescence lifetime imaging microscopy (FLIM) to examine for metabolic perturbations during culture.

Results: The mean age of patients across all time categories were comparable (35.6 ± 3.9). Live birth rates (38-52%) and miscarriage rate (5-11%) were not statistically different across post-warming culture time. When assessing pregnancy outcomes based on the use of PGT-A, miscarriage and live birth rates were not statistically different across culture hours in both PGT-A and non-PGT cycles. Further metabolic analysis of blastocysts for the duration of 10h of culture post warming, revealed minimal metabolic changes of embryos in culture.

Conclusion: Overall, our results show that differences in the time of post warming culture have no significant impact on miscarriage or live birth rate for frozen embryo transfers. This information can be beneficial for clinical practices with either minimal staffing or a high number of patient cases.

Keywords: Blastocyst culture; Embryo metabolism; FLIM; Frozen embryo transfer; In vitro fertilization.

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Conflict of interest statement

Tim H Sanchez and Colwyn Gulliford declare conflict of interest as they were members and shareholders of Optiva Fertility, Inc startup, which sponsored metabolic imaging. However, the startup did not move forward. All other authors declare no conflict of interest. No financial support was received for this study.

Figures

Fig. 1
Fig. 1
Study design. Vitrified blastocysts were warmed and transferred at different time points post warming. The categories for the warming to transfer time were the following: 0 (0- <1h), 1 (1<2h), 2 (2-<3h), 3(3-<4h), 4 (4-<5), 5 (5-<6), 6 (6-<7) and 7 (7-8h). The box shows the number of embryo transfers performed at each time category
Fig. 2
Fig. 2
Pregnancy outcomes assessed based on post warming culture period for non PGT-A versus PGT-A transfers. Pregnancy was assessed for clinical (fetal sac at ultrasound), live birth rate and miscarriage per transfer in relation to the categories for the warming to transfer time. Miscarriage rate in A) non-PGT-A group was between 6%-11% and in B) PGT-A group was between 3%-9%
Fig. 3
Fig. 3
FLIM parameters of human blastocysts. Metabolic signatures of human blastocysts were assessed in aneuploid (n=48) discarded human blastocyst stage embryos. The black line indicates the mean measurement. Orange lines indicate +/- standard error. Blue lines show measurements from individual embryos
See this image and copyright information in PMC

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References

    1. Mumusoglu S, Polat M, Ozbek IY, Bozdag G, Papanikolaou EG, Esteves SC, et al. Preparation of the Endometrium for Frozen Embryo Transfer: A Systematic Review. Front Endocrinol (Lausanne) 2021;12:688237. doi: 10.3389/fendo.2021.688237. - DOI - PMC - PubMed
    1. Roche K, Racowsky C, Harper J. Utilization of preimplantation genetic testing in the USA. J Assist Reprod Genet. 2021;38(5):1045–1053. doi: 10.1007/s10815-021-02078-4. - DOI - PMC - PubMed
    1. Bushaqer NJ, Alkhudhairy NN, Alturaigi ZM, Alhamad RM, Mohawesh WA, Alraka FE, et al. The effect of fresh IVF cycle characteristics on frozen embryo transfer (FET) outcomes. JBRA Assist Reprod. 2020;24(2):135–142. - PMC - PubMed
    1. ESHRE The Vienna consensus: report of an expert meeting on the development of ART laboratory performance indicators. Reprod Biomed Online. 2017;35(5):494–510. doi: 10.1016/j.rbmo.2017.06.015. - DOI - PubMed
    1. Veleva Z, Orava M, Nuojua-Huttunen S, Tapanainen JS, Martikainen H. Factors affecting the outcome of frozen-thawed embryo transfer. Hum Reprod. 2013;28(9):2425–2431. doi: 10.1093/humrep/det251. - DOI - PubMed

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