Blastocysts derived from 0PN oocytes: Genetic and clinical results

Abstract

Objective:To analyze the genetic and clinical outcomes of blastocysts derived from 0PN oocytes after IVF/ ICSI.Methods: This retrospective observational study included patients aged 40 years or younger submitted to IVF/ICSI with their own oocytes and with blastocysts derived from 0PN oocytes between January 2015 and April 2018. The clinical outcomes of 0PN blastocyst transfers were analyzed. Genetic tests were performed on biopsied 0PN blastocysts with Next Generation Sequencing.Results: A total of 27 0PN blastocysts were transferred, yielding an implantation rate of 48.0% and an ongoing pregnancy rate of 50.0%. The transfers resulted in 13 live births (59.0% live birth rate). Genetic test results revealed that four of the 17 0PN blastocysts biopsied were 46XX; three were 46XY; and 10 were aneuploid embryos, awarding a diploid rate to 76.4% (13/17).Conclusion: Almost half of the 0PN blastocysts implanted (48.0%) and 13 healthy babies were born. More than three quarters (76.4%) of the 0PN blastocysts were diploid, thus ruling out the possibility of parthenogenetic activation. Our study indicated that the transfer of 0PN blastocysts is a safe, worthy option when the number of normal 2PN embryos is insufficient.

Does the cell number of 0PN embryos on day 3 affect pregnancy and neonatal outcomes following single blastocyst transfer?

“…However, Li et al (2015) reported that 0PN blastocysts had similar clinical outcomes to 2PN blastocysts and advised culturing 0PN embryos to the blastocyst stage for selection. Consistent with these findings, recent studies have shown that blastocyst culture of 0PN embryos can result in notable clinical pregnancies and live births [ 5 , 7 – 9 ]. The quality and implantation potential of blastocysts can be predicted by the morphological parameters of cleavage-stage embryos, including the day 3 blastomere number, fragmentation and symmetry [ 11 , 12 ].…”

“…Generally, embryos derived from 0PN zygotes are not recommended for clinical use [ 1 ]. However, several studies have reported that these seemingly abnormal embryos can result in successful pregnancies and live birth after transfer, which has raised the value of 0PN embryos, especially for patients without two pronuclei (2PN) embryos [ 2 – 9 ]. Consequently, revealing the clinical value of 0PN embryos is important.…”

“…In addition, the health risks of 0PN offspring have gained extensive attention. To date, one retrospective study has reported that 0PN singletons had higher birthweights and Z-scores than 2PN singletons and that a greater proportion of 0PN singletons were very large for gestational age [ 8 ]; other previous studies, however, lacked information on neonatal outcomes from 0PN embryo transfers [ 3 , 5 , 7 , 9 , 14 ]. Thus, the safety of 0PN embryo transfers needs to be further investigated [ 8 ].…”

Clinical outcomes of frozen-thawed blastocysts from zygotes with no or one pronucleus for in vitro fertilization and intracytoplasmic sperm injection cycles

“…Some studies of the genetic characteristics of 0PN and 1PN embryos have suggested that a considerable number of 0PN and 1PN embryos may have a normal chromosomal composition, and thus may be considered for transfer when no embryos developing from 2PN zygotes are available [8][9][10]. Previous studies have reported that 0PN and 1PN cleavage stage embryos resulted in a lower implantation rate (IR) and live birth rate (LBR) when compared with 2PN cleavage stage embryos [11][12], while the IR and LBR were comparable between 0PN-and 1PN-derived blastocyst transfers and those of 2PN-derived blastocyst transfers [12][13]. However, some research suggested that 0PN-and 1PN-derived blastocyst transfers resulted in a lower IR and LBR than 2PN-derived blastocysts, especially in ICSI cycles [14][15].…”

Time-lapse monitoring of fertilized human oocytes focused on the incidence of 0PN embryos in conventional in vitro fertilization cycles

“…The primary reason for 0PN-derived embryos is thought to be due to PN being overlooked in the microscopic assessment at a fixed time point 1 . Some 0PN-derived embryos develop into morphologically normal blastocysts, and there are reports of healthy babies being born from their transfer [1][2][3][4][5][6][7][8][9][10] . However, transfer of the 0PN-derived embryo is not recommended as per the European Society of Human Reproduction and Embryology (ESHRE) guidelines; thus, most of them are discarded without being transferred 11 .…”