The Effects of Preimplantation Genetic Testing and Blastomere Biopsy Sampling on ICSI/IVF Embryos’ Development and Implantation

Background: Preimplantation genetic diagnosis (PGD) is a diagnostic approach in assisted reproductive technology (ART) to detect and select unaffected embryos to be transferred. Obtaining biopsy samples from embryos (polar body, blastomere, or blastocyst) is a key step in preimplantation genetic testing (PGT), which has many technical issues. Objectives: This study aimed to evaluate the effect of biopsies from 3-day embryos (blastomere) on the quality of embryos and implantation success in couples who requested sex selection before embryo transfer. Methods: On the third day after fertilization, 352 high-quality embryos (> six cells on day third with < 10% fragmentation) were collected from 77 women and were tested for sex selection using FISH testing. A laser beam was used to obtain blastomere biopsies by removing a significantly small portion of the zona pellucida. One blastomere was gently biopsied by an aspiration pipette through its hole. After biopsy sampling, the embryo was immediately returned to the embryo scope until transfer. Embryos’ integrity and blastocyst formation were assessed on day 5. Results: A total of 595 embryos were studied, including 352 embryos that were biopsied on day 3 for gender selection (i.e., the intervention group) and 243 intracytoplasmic sperm injection (ICSI) embryos that did not undergo biopsy (i.e., the control group). Overall, 17.1% of the embryos were abnormal for X or Y chromosomes. Biopsy for PGD was performed 67 - 73 hours after ICSI. Blastomere biopsy taking was significantly associated with blastocyst quality and implantation success. Conclusions: In this study, after obtaining blastomere biopsies, we investigated the growth process of the embryos according to morphokinetic parameters. Our results showed that blastomere biopsy taking could affect the blastulation of embryos and decrease the success rate of implantation.