Aneuploidy rates and blastocyst formation after biopsy of morulae and early blastocysts on day 5

Abstract

Purpose Studies have demonstrated high implantation rates after trophectoderm biopsy of day 5 expanded blastocysts. However, biopsy of cleavage stage embryos may adversely affect embryo development and implantation. No studies have assessed the utility of day 5 morulae and early blastocyst biopsy. This study sought to better understand these slower embryos' aneuploidy rates and implantation potential. Methods This was a retrospective review of all autologous IVF cycles utilizing PGS at a single academic infertility center. Results The biopsy of day 5 morulae and early blastocysts provided 22 % additional euploid blastocysts available for fresh day 6 transfer compared to day 5 biopsy of only expanded blastocysts. Aneuploidy did correlate with embryo stage on day 5, even after controlling for maternal age, with 16 % of morulae and 35 % of blastocysts being euploid. The majority (83 %) of euploid morulae progressed to the blastocyst stage by day 6. Experience transferring slower developing embryos is limited, but preliminary pregnancy and implantation rates appear similar to euploid embryos biopsied as expanded blastocysts.Conclusions The biopsy of all non-arrested embryos on day 5 provides genetic information for all blastocysts on day 6, increasing the pool of euploid blastocysts available for fresh transfer and avoiding the need to cryopreserve developmentally competent embryos without genetic information.

Elective single blastocyst transfer in advanced maternal age

“…The significance of slow-growing embryos is still evolving. A recent study has shown that EBs that became FEBs on day 6 were less likely to be euploid compared to FEBs on day 5 (23 vs. 41%, p < 0.05) [23]. A second study demonstrated similar results, with a higher aneuploidy rate of EBs compared to those of FEBs (70 vs. 61%, p < 0.05) [24].…”

Euploidy in relation to blastocyst sex and morphology

“…Patients underwent controlled ovarian stimulation using antagonist, long GnRH agonist (leuprolide acetate), or microdose flare protocols ( Table 1). Embryos were cultured according to methods previously described [11]. Briefly, embryos were group cultured in SAGE sequential media in low oxygen conditions.…”

Microarray Analyses Reveal Marked Differences in Growth Factor and Receptor Expression Between 8-Cell Human Embryos and Pluripotent Stem Cells

“…Attempts to derive stem cell lines from individual 8C blastomeres from the mouse, cow, and human essentially fail, in that only a small percentage of the blastomeres continue to divide when separated from sisters [ 37–39 ]. This suggests either that paracrine signaling is essential for further cell division at this stage or that aneuploidy incompatible with independent continued cleavage is common in blastomeres in early embryos, as has been suggested [ 20 , 40 ], or both.…”