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Background: Embryo quality may be accurately assessed as early as the pronuclear zygote phase, as shown in recent studies. However, it is not known whether good quality zygotes are destined to become good quality cleavage stage embryos and blastocysts.Methods: In this retrospective study, 86 intracytoplasmic sperm injection-embryo transfer cycles were studied where each available embryo was scored from the zygote until the blastocyst stage. Embryonic normality parameters such as pronuclear pattern, early cleavage, cleavage stage embryo grade, the presence of embryos with > or =8 cells on day 3 and blastocyst quality were recorded. Embryo transfer was undertaken at the blastocyst stage and the outcome was studied according to the pronuclear pattern exhibited by the zygotes.Results: Embryos that showed an ideal pronuclear pattern (0 PN pattern) cleaved earlier and faster and resulted in better quality cleavage stage embryos and blastocysts. The incidence of blastocyst formation was 72% in zygotes showing a 0 PN pattern, compared with 12.7% in zygotes with double pronuclear abnormality. Higher implantation and pregnancy rates were obtained when at least one blastocyst derived from a 0 PN pattern zygote was included in the set of embryos to be transferred.Conclusions: Our results indicate that the pronuclear pattern of the zygote is closely related to blastocyst formation and quality. Blastocysts derived from 0 PN zygotes have a higher potential for implantation. [ABSTRACT FROM AUTHOR]

Recent studies indicate a strong paternal influence on embryo development and progression of the embryo to the blastocyst stage. The aim of this study was to compare, during extended culture, the in-vitro development of embryos resulting from intracytoplasmic sperm injection (ICSI) of ejaculated spermatozoa (group 1, n = 347), epididymal (group 2, n = 22) or testicular (group 3, n = 18) spermatozoa from obstructive azoospermic and testicular spermatozoa from non-obstructive azoospermic (group 4, n = 31) subjects. Fertilization and blastocyst formation rates were significantly lower in group 4 (P < 0.05). The incidence of expanded and hatching blastocysts was significantly lower in group 4 (P < 0.05). Overall in 93.2% ejaculate ICSI cycles, blastocysts were transferred on day 5. This was significantly higher than the 62% day 5 transfers in the non-obstructive azoospermic group (P < 0.05). Implantation rate per embryo was significantly higher in the ejaculate ICSI group compared with the other groups (P < 0.05). Clinical pregnancy per transfer was similar between groups; however, significantly fewer multiple pregnancies were encountered in the non-obstructive azoospermic group (P < 0.01). In conclusion, the source of the spermatozoa, most likely to be indicative of the severity of spermatogenic disorder, affects the rate of blastocyst formation and blastocyst implantation. Spermatozoa from non-obstructive azoospermic subjects, when utilized for ICSI, result in embryos that progress to the blastocyst stage at a lower and slower rate and implant less efficiently. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate whether the extraction of testicular spermatozoa with percutaneous versus open biopsy has an effect on the treatment outcome with intracytoplasmic sperm injection (ICSI) in men with non-obstructive azoospermia. Regardless of testicular size, follicle stimulating hormone concentration, and previous biopsy result, percutaneous testicular sperm aspiration (PTSA) using a 21-gauge butterfly needle was attempted first and if this failed testicular sperm extraction (TESE) was performed. In 63 men spermatozoa were found with PTSA whereas in 228 men TESE had to be undertaken. More men in the PTSA group had previously been diagnosed with hypospermatogenesis (82 versus 50%). Compared with the PTSA group, more men in the TESE group had germ cell aplasia (27 versus 10%) or maturation arrest (22 versus 8%). There was no difference between the groups regarding mean age of men and their partners, duration of stimulation, oestradiol concentration on the day of human chorionic gonadotrophin, number of oocytes retrieved, fertilization rate, and embryo quality between the two groups. The number of embryos transferred (4.38 versus 3.90) was significantly higher in the PTSA group (P < 0.05), reflecting the increased number of embryos available for transfer. Implantation rate per embryo was 20.7% in the PTSA and 13.3% in the TESE group (P < 0.05). Clinical pregnancy rates were 46 and 29% in the PTSA and TESE groups respectively (P < 0.05). Clinical abortion rates were similar (21.2 versus 24%). It is concluded that in men with non-obstructive azoospermia, easier sperm retrieval, which is most likely indicative of a more favourable histopathology, is associated with higher implantation rates per embryo. [ABSTRACT FROM AUTHOR]

Progression to the blastocyst stage of embryos derived from testicular round spermatids in men with non-obstructive azoospermia was studied. A total of 56 men were studied in whom partial spermatogenesis failure had occurred where only very few spermatozoa (fewer than the number of oocytes retrieved) were extracted from multiple testicular biopsy specimens. Oocytes remaining after intracytoplasmic injection of testicular spermatozoa (group 1) were injected with round spermatids (ROSI, group 2). Only embryos derived from group 1 were transferred. Remaining embryos were observed under culture for 8 days and their progression to the blastocyst stage was recorded. Of the 546 oocytes injected with testicular spermatozoa, 404 (73.9%) showed evidence of 2-pronuclear (2PN) fertilization. Injection of testicular round spermatids resulted in 2PN fertilization rate of 50% (P < 0.05). Using a four-point grading system, 53% of the good quality embryos (grade 1 or 2) in group 1 reached the blastocyst stage compared with 25% in group 2 (P < 0.05). The rate of progression to the blastocyst stage of grade 3 and grade 4 embryos was 46 and 8.5% in the two groups respectively (P < 0.05). Using a different three-point grading system for the blastocysts, 75.3% of the blastocysts in group 1 were either grade 1 or grade 2 and 24.7% were grade 3. However, in group 2 all blastocysts were grade 3. All embryos observed in group 1 reached the blastocyst stage by day 5 or 6 compared with 25% of the embryos reaching the blastocyst stage by this time in group 2. While 31.2% of the blastocysts in group 1 showed evidence of spontaneous hatching in vitro, none of the blastocysts in group 2 hatched. In conclusion, progression to the blastocyst stage occurred at a much lower and slower rate in embryos derived from testicular round spermatids. Furthermore, all blastocysts resulting from ROSI were of poor quality and none showed spontaneous hatching. These results may explain the dismal outcome associated with ROSI. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the effect of 24-h in-vitro culture of testicular spermatozoa in recombinant follicle stimulating hormone (recFSH) supplemented medium versus simple medium on sperm motility, and to analyse the outcome of intracytoplasmic sperm injection (ICSI) of such spermatozoa. A total of 143 positive testicular sperm extraction procedures in men with non-obstructive azoospermia was evaluated prospectively. Extracted testicular tissue samples were randomized to be cultured in vitro for 24 h in simple medium or recFSH supplemented media. ICSI was performed with spermatozoa cultured in recFSH (n = 73) or in simple medium (n = 70). Sperm motility following in-vitro culture, embryo quality after ICSI, and implantation and pregnancy rates were assessed. Of the 898 MII oocytes available in the recFSH group, 646 (71.9%) were injected with spermatozoa showing either twitching or progressive motility. However, only 29.1% of the oocytes in the simple medium group (245/841) were injected with motile spermatozoa (P < 0.05). Fertilization rate (68.8 versus 42.1%), implantation rate per embryo (20.1 versus 13.2%), and clinical pregnancy rate (47. 9 versus 30%) were significantly increased in the recFSH group compared with the simple medium group respectively (P < 0.05). In conclusion, in-vitro culture with recFSH appears to increase the motility of testicular spermatozoa, thus increasing the success of ICSI. [ABSTRACT FROM AUTHOR]