We examined whether partial thinning of zona pellucida by a LAH (laser-assisted hatching) system in ICSI could ease pressure on the egg and influence the results of subsequent embryogenesis and pregnancy rate (90 subjects, 101 cycles). ICSI was performed with and without thinning of zona pellucida in a thinning group and a control group, respectively, and the results of embryogenesis and pregnancy rate were compared between the two groups. Fertilization rate, oocyte degeneration rate, good embryo rate, and pregnancy rate in early embryo implantation were higher, though not significantly in the thinning group (80.8%, 7.5%, 66.5%, and 28.6%) than in the control group (73.0%, 9.7%, 64.6%, and 23.1%). The fertilization rate was significantly higher in the thinning group compared to the control group. Our results suggest that partial thinning of zona pellucida using a LAH system is useful in ICSI.

Three ICSI methods were examined to determine their clinical efficiency and the mechanisms of oocyte damages. The volumes of cytoplasm aspirated into the ICSI pipette at oolemma breakage, the sizes of the broken areas in the oolemma and the rates of oocyte lysis and fertilization after sperm injections were compared. The three ICSI methods were Conventional-ICSI (CI), Conventional Piezo-ICSI (CPI) (using standard 1 µm thickness micropipettes) and Improved Piezo-ICSI (IPI) (using ultra-thin 0.5 µm thickness micropipettes). The volumes of cytoplasm aspirated into the ICSI pipette at oolemma breakage in CI, CIP and IPI were 2792 ± 952, 0 ± 0 and 0 ± 0 µm³, respectively. Significantly, the greatest volume of cytoplasm aspirated into the ICSI pipette (P<0.0001) was observed in the CI method. The sizes of the broken areas in the oolemma in CPI and IPI were 18 and 8 µm², respectively. The rates of lysis and fertilization after CI, CPI and IPI were 10, 5 and 1%, and 78, 79 and 89%, respectively. Significantly, the lowest lysis rate (P<0.0001) and highest fertilization rate (P=0.0021) were obtained by the IPI method. The results show that the IPI method is the best ICSI method as it reduced the broken area in the oolemma at sperm injection, and resulted in the lowest oocytes lysis and highest fertilization rates.

Japan Society of Ova Research (JSOR) is the certifying boards for embryologists engaged in assisted reproductive technology (ART). JSOR has certified 1,006 Embryologists of Assisted reproductive technology from 2002 until now and 14 Senior embryologists of assisted reproductive technology from 2007 until now. We analyzed certified embryologists in order to know the present status of embryologist. About certified embryologists, a woman occupied 79.8%. The range of 20–29 years old was the most (71.3%). By analysis of last educational background, 63.7% of them was a graduate from a university / a graduate school. The embryologist who acquired a degree was 24.3%. One to two years of the engagement period in the ART laboratory was the most (48.8%). The most common type of ART facility where embryologists engaged in is a private clinic (69.1%). Fourteen senior embryologists of ART were certified in collaboration with Japan society of reproductive medicine. Currently, embryologist is widely recognized as an occupation. A public qualification system will be needed for the development of embryologist.