No abstract

Comprehensive chromosome screening and follow-up assessment of large numbers of cells provided a unique insight into the cytogenetics of human blastocysts. Meiotic and post-zygotic errors leading to mosaicism were common. However, most mosaic blastocysts contained no normal cells. Hence, CGH or aCGH TE analysis is an accurate aneuploidy detection tool and may assist in identifying viable euploid embryos with higher implantation potential.

Semi-automatic grading of human blastocysts by a computer is feasible and may offer a more precise comparison of embryos, reducing subjectivity and allowing embryos with apparently identical morphological scores to be distinguished.

The implantation rates achieved with intracytoplasmic sperm injection (ICSI) are equivalent to those with conventional in-vitro fertilization (IVF) but information on embryonic development in vitro after ICSI is scant. In this paper we compare blastocyst formation after IVF and ICSI; we have also investigated the effect of the ICSI procedure with internal control of extrinsic (including paternal) factors. The first series comprised cases of IVF treatment (n = 101) for tubal infertility and ICSI (n = 96) for male infertility. The proportions of embryos developing to the blastocyst stage was significantly lower after ICSI (8.9%, P < 0.001) than after conventional IVF (23.5%). In order to investigate the effect of the ICSI procedure in isolation, blastocyst formation was analysed in a second series of eight cases, in which sibling oocytes were non-selectively subjected to ICSI (n = 78) or IVF (n = 67) with spermatozoa from the same semen sample. It was found that 20% of ICSI embryos and 50% of IVF embryos formed blastocysts (P < 0.01), demonstrating that the ICSI procedure contributes to a reduced capacity for blastocyst formation in vitro.

This review discusses the current status of laser-assisted reproductive technologies in human infertility treatment. We highlight the benefits of laser technology in diagnostic and therapeutic treatments for subfertility and male-factor infertility, and current concern of this application in different clinical practice. ABSTRACTTo improve success rates, assisted reproductive technology (ART) procedures continually undergo optimization and enhancement such that the best quality gametes and embryos can be identified and manipulated, thus improving clinical outcomes. Laser technology is now being applied across ART to reduce procedure times and increase the consistency and reproducibility of traditional ART techniques such as assisted hatching, embryo biopsy, intracytoplasmic sperm injection cryopreservation and sperm immobilization/selection. This review examines the current status of cutting-edge laser-assisted reproductive technologies, investigates experimental techniques that are increasingly being applied clinically. It highlights the benefits of lasers as a powerful technology at the forefront of both diagnostic and therapeutic treatments for general subfertility and male-factor infertility. However, it is important to note that although lasers are becoming increasingly commonplace in ART units, there is comparatively little information in the existing literature pertaining to the potential negative effects that laser application might have on the developing human embryo, thus creating the need for further investigative research.