Live birth rates after different endometrial preparation methods in frozen cleavage-stage embryo transfer cycles: a randomized controlled trial

Background: Studies have suggested that embryo-endometrial developmental asynchrony caused by slow-growing embryos can be corrected by freezing the embryo and transferring it back in a subsequent cycle. Therefore, we hypothesized that live birth rates (LBR) would be higher in frozen embryo transfer (FET) compared with fresh embryo transfers. Objective: To compare LBR between fresh and FET cycles. Materials and Methods: A cross-sectional analysis of 10,744 single autologous embryo transfer cycles that used a single cleavage-stage embryo was performed. Multivariate analysis was performed to compare LBR between FET and fresh cycles, after correcting for various confounding factors. Sub-analysis was also performed in cycles using slow embryos. Results: Both LBR (19.13% vs 14.13%) and clinical pregnancy (22.48% vs 16.25%) rates (CPR) were higher in the fresh cycle group (p < 0.00). Multivariate analysis for confounding factors also confirmed that women receiving a frozen-thawed embryo had a significantly lower LBR rate compared to those receiving a fresh embryo (OR 0.76, 95% CI 0.68-0.86, p < 0.00). In the sub-analysis of 1,154 cycles using slow embryos, there was no statistical difference in LBR (6.40% vs 6.26%, p = 0.92) or CPR (8.10% vs 7.22%, p = 0.58) between the two groups. Conclusion: This study shows a lower LBR in FET cycles when compared to fresh cycles. Our results suggest that any potential gains in LBR due to improved embryo-endometrial synchrony following FET are lost, presumably due to freeze-thaw process-related embryo damage. Key words: Fresh, Frozen embryo transfer, Live birth, Embryo, Transfer.

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Blastocyst transfer increases cumulative-live-birth-rates and reduces time and cost to livebirth compared with cleavage stage in recipients of donated oocytes. A randomized controlled trial

Reproductive BioMedicine Online ◽

10.1016/j.rbmo.2022.01.001 ◽

2022 ◽

Author(s):

E. Clua ◽

I. Rodríguez ◽

G. Arroyo ◽

A. Racca ◽

F. Martínez ◽

...

Keyword(s):

Randomized Controlled Trial ◽

Live Birth ◽

Controlled Trial ◽

Blastocyst Transfer ◽

Cleavage Stage ◽

Birth Rates ◽

Live Birth Rates ◽

Randomized Controlled ◽

Cumulative Live Birth

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Effect of Age and Morphology on Live Birth Rate After Cleavage Stage Embryo Transfer

Reproductive Sciences ◽

10.1007/s43032-020-00249-9 ◽

2020 ◽

Vol 28 (1) ◽

pp. 43-51

Author(s):

Michael Awadalla ◽

Nicole Vestal ◽

Lynda McGinnis ◽

Ali Ahmady

Keyword(s):

Embryo Transfer ◽

Live Birth ◽

Birth Rate ◽

Live Birth Rate ◽

Cleavage Stage ◽

Birth Rates ◽

Live Birth Rates ◽

Cleavage Stage Embryo ◽

Stage Embryo ◽

Best Fit

AbstractAccurate knowledge of the live birth rate for cleavage stage embryos is essential to determine an appropriate number of embryos to transfer at once. Results from previous studies lack details needed for practical use. This is a mathematical analysis and model building study of day 3 cleavage stage embryo transfers. A total of 996 embryos were transferred in 274 fresh and 83 frozen embryo transfers. Embryo morphology was divided into 4 groups based on number of cells and fragmentation percentage. Each embryo transfer was modeled as an equation equating the sum of the live birth rates of the transferred embryos to the number of live births that resulted. The least squares solution to the system of embryo transfer equations was determined using linear algebra. This analysis was repeated for ages 35 to 42 years old at oocyte retrieval. The best fit live birth rates per embryo in the age group centered on 35 years old were 29%, 13%, 10%, and 9% for embryos in the 8-cell with ≤ 5% fragmentation, 8-cell with > 5% fragmentation, 9–12 cell, and 6–7 cell groups, respectively. Cleavage stage embryos with fewer than 6 cells on day 3 had very low best fit live birth rates close to 0% at age 39 years and were excluded from the primary analysis to prevent overfitting. These live birth rates can be used with a simple embryo transfer model to predict rates of single and multiple gestation prior to a planned cleavage stage embryo transfer.

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