of transfers 47 41 NA Mean age of recipients 42.0 ± 6.8 42.9 ± 6.7 0.24 # of chemical pregnancy (%)\* 37 (78.7) 26 (63.4) 0.11 # of clinical pregnancy (%)\*\* 35 (74.5) 25 (61.0) 0.18 # of live birth (%) 33 (70.2) 24 (58.5) 0.25 # of blastocysts transferred 59 63 NA # of blastocyst implanted 37(62.7) 31 (49.2) 0.11

**One-step method Two-step method P value**

As shown in **Figure 3**, aneuploidies occurred in all chromosomes except chromosome 12 and the differences for each chromosome were not statistically signifi-

*Comparison of clinical outcomes after transfer of euploid blastocysts biopsied by one-step and two-step* 

outcomes were observed when one-step biopsy method was used.

As shown in **Table 3**, transfer of euploid blastocysts biopsied by one-step method had higher chemical pregnancy (78.7 vs. 63.4%), clinical pregnancy (74.5 vs. 61.0%), live birth (70.2 vs. 58.5%) and embryo implantation rates (62.7 vs. 49.2%) as compared with transfer of euploid blastocysts biopsied by two-step method. Although these rates were not statistically significant between two groups, improved clinical

Recently Munne *et al.* found that euploidy rate in human embryos produced by donor egg IVF differed significantly between infertility clinics [12], but they did not analyze the cause(s) related to these differences. Because they collected data from multiple IVF clinics and each clinic used different biopsy methods, which may make it difficult to analyze these factors. In the present study, to minimize the effects of maternal age-related aneuploidy formation in the embryos [6, 13–15, 17–20], we also used donor egg IVF cycles to examine whether biopsy methods affect embryo aneuploidies. Our data indicate that biopsy methods do not affect embryonic aneuploidies, however, simplified biopsy method may improve embryo implantation that may be benefited from reduced embryo manipulations and limited laser applications. We also found that high proportions of human embryos from donor egg IVF are not only whole chromosome aneuploidy, but also have

Although most of embryonic aneuploidies have already occurred before oocyte and sperm are collected for IVF due to meiotic error(s) during oocyte and sperm development [1–3], some of aneuploidies may be caused by mitotic errors, or suboptimal in vitro conditions and/or in vitro manipulations [1]. Rigorous temperature control during oocyte manipulations can maintain meiotic spindle integrity that may prevent meiosis error during final oocyte maturation after egg retrieval [1]. While embryo biopsy for PGT-A is still an invasive laboratory procedure, thus different methods may affect the embryo quality including chromosome integrity. Since laser was used to zona hole opening and blastocyst biopsy in human IVF, it has made the biopsy procedure to be easy [21]. However, excess use of laser pulses

*DOI: http://dx.doi.org/10.5772/intechopen.95457*

cant between two methods.

*methods from donor egg cycles.*

segmental chromosome abnormalities.

**4. Discussion**

*\**

**Table 3.**

*Positive beta hCG. \*\*Fetus with heartbeat. NA: Not applicable.*

*Next-Generation Sequencing Revealed that High Proportion of Human Embryos Resulted… DOI: http://dx.doi.org/10.5772/intechopen.95457*


#### **Table 3.**

*Cytogenetics - Classical and Molecular Strategies for Analysing Heredity Material*
