Association of the duration of post-thaw culture with clinical outcome after vitrified-warmed day 3 embryo transfer in 10,464 cycles: A retrospective cohort study

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

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.

Effect of post‐warming culture time on the live birth rate after frozen embryo transfer

Purpose

Methods

Results

Conclusions

Does Post-Warming Extended Culture Duration Affect the Clinical and Obstetric Outcomes of Patients of Advanced Maternal Age? A Single-Center Study

BACKGROUND

The single vitrified-warmed blastocyst transfer (SVBT) cycle has been increasingly utilized for assisted reproductive technology. Women of advanced maternal age (AMA) comprise a significant portion of patients who have undergone 'freeze-all' cycles. This study investigated the association between the post-warming extended culture duration and pregnancy outcomes in patients of AMA.

METHODS

This retrospective cohort study analyzed the outcomes of 697 SVBT cycles between January 2016 and December 2017. The cycles were divided into 3 groups based on the age of the female partners: group I: < 35 years (n = 407), group II: 35-37 years (n = 176); and group III, 38-40 years (n = 114). Data are shown as the mean ± standard error of the mean. Data were analyzed using one-way ANOVA followed by Duncan's multiple range test. Statistical significance was set at P < 0.001.

RESULTS

The blastocyst rate, clinical pregnancy rate, and live birth rate (LBR) was significantly lower in the AMA groups. However, there were no significant differences in LBR in the transfer between the AMA and younger groups according to blastocyst morphology and post-warming extended culture duration.

CONCLUSION

Post-warming extended culture of blastocysts is not harmful to patients of AMA. It could be a useful parameter in clinical counseling and decision making for fertility treatments.