Impact of polar body biopsy on embryo morphokinetics—back to the roots in preimplantation genetic testing?

Abstract

PurposePolar body biopsy (PBB) is a common technique in preimplantation genetic testing (PGT) to assess the chromosomal status of the oocyte. Numerous studies have been implemented to investigate the impact of biopsies on embryo development; however, information on embryo morphokinetics is still lacking. Hence, we investigated the impact of PBB on morphokinetic parameters in early embryo development.MethodsFour hundred four embryos (202 PBB, 202 control) were retrospectively analyzed. Patients were stimulated with a gonadotropin-releasing hormone antagonist ovarian hyperstimulation protocol. After fertilization check, embryos were incubated in a time-lapse incubator. The groups were matched for maternal age at time of oocyte retrieval.ResultsMean group times for reaching specific developmental time points showed no significant difference comparing embryos with PBB conducted and without. Likewise, further subdivision of the PBB group in euploid and aneuploid embryos revealed no differences in the early embryo morphokinetic development compared to the control group. Aneuploidy testing revealed a high prevalence of chromosomal aberrations for chromosomes 21, 4, 16, and 19.ConclusionsIn conclusion, PBB does not impact the morphokinetic parameters of the embryo development. PBB can be safely applied without the risk of impairing the reproductive potential of the embryo and can be highly recommended as safe and practicable PGT approach, especially in countries with prevailing restrictions regarding PGT analysis.

Novel Time-Lapse Parameters Correlate with Embryo Ploidy and Suggest an Improvement in Non-Invasive Embryo Selection

“…However, only maternal genetic information is obtained. Although 90% of human aneuploidies at birth are of maternal origin, the possibility of paternal aneuploidies cannot be dismissed [29].…”

Evolution of Minimally Invasive and Non-Invasive Preimplantation Genetic Testing: An Overview

“…In addition, PB biopsy is applicable in countries with strict legislation against day-three biopsy or biopsy after syngamy. Nevertheless, the major drawback of this type of biopsy is the need for primary and secondary PBs; it is also relatively labor-intensive, only maternal chromosomes are examined, and it is not applicable in cases of abnormal paternal genetic contribution [13].…”

Preimplantation genetic testing: A narrative review

“… 15 A more recent study supported that PB biopsy does not have a negative impact on embryo development and neonatal outcomes while also demonstrating no differences in biochemical pregnancy rates and implantation events, concluding that PB biopsy is a safe approach. 16 …”

“…15 A more recent study supported that PB biopsy does not have a negative impact on embryo development and neonatal outcomes while also demonstrating no differences in biochemical pregnancy rates and implantation events, concluding that PB biopsy is a safe approach. 16 According to the ESHRE PGT Consortium data collection XXI, in 2018, PB biopsy was used in just 1% of PGT-M, PGT-SR, and PGT-A, similar to the respective 2%, 1%, and 3% used in 2016-2017. 17,18 Blastomere biopsy at the cleavage stage consists of the extraction of one blastomere from day 3 embryos, when they have 6 to 8 cells.…”