ICSI in late matured oocytes, is it worth it? Study with laboratory, clinical and genetic evaluation results.

OBJECTIVE: To compare laboratory results of embryo development from late matured oocytes in relation to mature oocytes in D+0. METHODS: We carried out a cross-sectional study during the period from January to December 2018, in which we collected data through medical records analysis. 913 oocytes were collected and divided into 3 groups: group 1 - 643 MII oocytes; group 2 - 119 MI oocytes and; group 3 - 151 PI oocytes. These studied oocytes were from different maternal ages and infertility factors. The analyzed variables were fertilization rate, embryo cleavage, top quality embryos on the third day of development, blastocyst stage, top quality blastocysts, euploid blastocysts, top quality blastocysts and gestation. We documented the data, and performed the statistical analysis using the chi-square test (p<0.05). RESULTS: All MII oocytes were injected (643); 103/119 MI oocytes and 88/151 PI oocytes that matured late in D + 1, were also injected. The fertilization rate of the three groups did not present statistical difference. The oocytes of group 1 had a statistically proven better prognosis than oocytes from groups 2 and 3 when compared, respectively, embryo cleavage (p=0.000), top quality embryos on the third day of development (p=0.000) and blastocyst formation rate (p=0.004). In the LMO group, there were no euploid embryos and, therefore, there no embryo transfer. CONCLUSION: Although late matured oocytes have made blastocyst formation possible, even if in low rates, there were no viable embryos for transfer.