Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Meta-Analysis
. 2022 Jan;29(1):43-53.
doi: 10.1007/s43032-020-00424-y. Epub 2021 Jan 15.

Clinical Outcomes Deriving from Transfer of Blastocysts Developed in Day 7: a Systematic Review and Meta-Analysis of Frozen-Thawed IVF Cycles

Laura Corti  1 , Greta Chiara Cermisoni  2 , Alessandra Alteri  1 , Luca Pagliardini  2 , Guido Ambrosini  3 , Alessandra Andrisani  3 , Enrico Papaleo  1 , Paola Viganò  4 , Marco Noventa  3
Affiliations
Meta-Analysis

Clinical Outcomes Deriving from Transfer of Blastocysts Developed in Day 7: a Systematic Review and Meta-Analysis of Frozen-Thawed IVF Cycles

Laura Corti et al. Reprod Sci. 2022 Jan.

Abstract

This meta-analysis aimed to assess the reproductive competence of blastocysts developed on day 7 compared with blastocysts developed on day 5/6. A systematic search was carried out to select relevant studies published before January 2020. Ten retrospective observational cohort studies were included. The primary outcome was the clinical pregnancy rate (CPR). Secondary outcomes were live birth rate (LBR), euploid rate, and survival rates after thawing. Frozen-thawed day 7 blastocyst transfer was associated with a significant reduction in CPR compared to day 5/6 (OR 0.36 95% CI 0.21 to 0.62, p = 0.0002, I2 = 71% and OR 0.43, 95% CI 0.32 to 0.58, p < 0.0001, I2 = 17% respectively). A significantly lower proportion of LBR was found comparing blastocysts transfers in day 7 to those in day 5/6 (OR 0.21, 95% CI 0.16-0.27, p < 0.0001, I2 = 0% and OR 0.34, 95% CI 0.26-0.45, p < 0.0001, I2 = 0% respectively). These findings were confirmed in a subgroup of Preimplantation Genetic Testing for Aneuploidies (PGT-A)-screened blastocysts. Blastocysts biopsied in day 7 was associated with a significant decrease of euploid rate compared with day 5/6 (OR 0.47, 95% CI 0.39-0.57, p < 0.0001, I2 = 69% and OR 0.68, 95% CI 0.61-0.75, p < 0.0001, I2 = 19% respectively). The survival rate after thawing was not statistically different. Sensitivity analyses were also performed. This study shows an association between delayed blastulation and a poorer prognosis in terms of euploid rate and pregnancy outcomes following frozen-thawed transfers. On the other hand, the results do not support the discharge of slow-blastulation embryos.

Keywords: Clinical pregnancy rate (CPR); Day 7 blastocyst; Euploid rate; Frozen embryo transfer; Live birth rate (LBR).

PubMed Disclaimer

References

    1. Alpha Scientists in Reproductive Medicine and ESHRE Special Interest Group of Embryology. The Istanbul consensus workshop on embryo assessment: proceedings of an expert meeting. Hum Reprod. 2011;26(6):1270–83. - DOI
    1. Sunkara SK, Siozos A, Bolton VN, Khalaf Y, Braude PR, El-Toukhy T. The influence of delayed blastocyst formation on the outcome of frozen-thawed blastocyst transfer: a systematic review and meta-analysis. Hum Reprod. 2010;25(8):1906–15. - DOI
    1. Bourdon M, Pocate-Cheriet K, Finet de Bantel A, Grzegorczyk-Martin V, Amar Hoffet A, Arbo E, et al. Day 5 versus day 6 blastocyst transfers: a systematic review and meta-analysis of clinical outcomes. Hum Reprod. 2019;34(10):1948–64. - DOI
    1. Hammond ER, Cree LM, Morbeck DE. Should extended blastocyst culture include day 7? Hum Reprod. 2018;33(6):991–7. - DOI
    1. Du T, Wang Y, Fan Y, Zhang S, Mol B, Lyu Q, et al. Pregnancy and neonatal outcomes of embryos achieving blastulation on day 7: are they of clinical value? Hum Reprod. 2018;33(6):1038–51. - DOI

Publication types

LinkOut - more resources