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
. 2022 Jan;39(1):173-181.
doi: 10.1007/s10815-021-02365-0. Epub 2022 Jan 3.

Embryo attrition in planned PGT-A: predicting the number of available blastocysts for transfer

C E Gordon  1 , K W Keefe  2 , E S Ginsburg  2 , C Racowsky  2 , A Lanes  2
Affiliations

Embryo attrition in planned PGT-A: predicting the number of available blastocysts for transfer

C E Gordon et al. J Assist Reprod Genet. 2022 Jan.

Abstract

Purpose: During a typical IVF cycle, there is unavoidable attrition from oocytes retrieved to blastocysts formed. Some patients will not have blastocysts available to biopsy or embryos for transfer. The purpose of this study was to predict the number of transferable blastocysts available for patients based on their age and number of 2pn zygotes.

Methods: This was a retrospective cohort study of all fresh autologous IVF and ICSI cycles in which PGT-A was planned from 1/2012 to 3/2020. In total, 746 cycles from 571 patients were analyzed. Patient cycles were stratified into two groups: less than four 2pn zygotes (n = 85) and at least four 2pn zygotes (n = 661). Cycles were then stratified by patient age. Cycle outcomes, including number of cleavage-stage embryos, blastocysts, euploid blastocysts, and low level mosaic blastocysts, were determined.

Results: Cleavage-rate was independent of age and number of 2pn zygotes and ranged between 96 and 100%. Blastocyst conversion and euploid blastocyst conversion rates were directly correlated to age, ranging from 52 to 83% for blastocyst conversion and 0-28% for euploid blastocyst conversion. For patients above the age of 40 years with less than four 2pn zygotes, the risk of having no transferable embryos was 99.7%.

Conclusion: While the literature demonstrates higher live birth rates with the use of PGT-A in women of advancing age, this is inconsequential if there is no embryo available to transfer. Women over 40 years with less than four 2pn zygotes should consider transfer of one or more untested embryos either on day 3 or on day 5.

Keywords: Blastocyst; Embryo culture; Euploidy; IVF; IVF attrition; PGT-A.

PubMed Disclaimer

Conflict of interest statement

The authors declare no competing interests.

References

    1. Forman EJ, Hong KH, Ferry KM, Tao X, Taylor D, Levy B, et al. In vitro fertilization with single euploid blastocyst transfer: a randomized controlled trial. Fertil Steril. 2013;100:100–107.e1. doi: 10.1016/j.fertnstert.2013.02.056. - DOI - PubMed
    1. Scott RT, Upham KM, Forman EJ, Hong KH, Scott KL, Taylor D, et al. Blastocyst biopsy with comprehensive chromosome screening and fresh embryo transfer significantly increases in vitro fertilization implantation and delivery rates: a randomized controlled trial. Fertil Steril. 2013;100:697–703. doi: 10.1016/j.fertnstert.2013.04.035. - DOI - PubMed
    1. Yang Z, Liu J, Collins GS, Salem SA, Liu X, Lyle SS, et al. Selection of single blastocysts for fresh transfer via standard morphology assessment alone and with array CGH for good prognosis IVF patients: results from a randomized pilot study. Mol Cytogenet. 2012;5:24. doi: 10.1186/1755-8166-5-24. - DOI - PMC - PubMed
    1. Munné S, Kaplan B, Frattarelli JL, Child T, Nakhuda G, Shamma FN, et al. Preimplantation genetic testing for aneuploidy versus morphology as selection criteria for single frozen-thawed embryo transfer in good-prognosis patients: a multicenter randomized clinical trial. Fertil Steril. 2019;112:1071–1079.e7. doi: 10.1016/j.fertnstert.2019.07.1346. - DOI - PubMed
    1. Glujovsky D, Farquhar C, Quinteiro Retamar AM, Alvarez Sedo CR, Blake D. Cleavage stage versus blastocyst stage embryo transfer in assisted reproductive technology. Cochrane Database Syst. 2016;30:(6):CD002118. - PubMed