After standard in vitro fertilization (IVF) chromosome analysis of uncleaved oocytes has shown that in about 80% of the cases, there was no fertilization at all while in 10% of the cases there was a premature chromosome condensation and a development arrest. After micro-injection our results suggest that both the technique itself and the pathologies which require micro-injection can influence the results. On the other hand about 20-30% of the metaphase II oocytes are cytogenetically abnormal after IVF attempt while ICSI might increase chromosome breakage. Our results suggest that both the technique used and the gamete pathologies can influence the different steps of development arrest.