Objectives: Determine the number of metaphase II oocytes that are needed for optimum rate blastulation and get a better rate of gestation. Design: Retrospective study. Institution: Fertility Unit -Hospital Alcivar Guayaquil (Ecuador). Participants: Women diagnosed with infertility. Interventions: There were 110 women in which they are performed IVF-ICSI, excluding 3rd and transfer canceled cycles. After controlled ovarian stimulation, cultivation continues to blastocysts. Main outcome measures: Rate of metaphase II oocytes, pregnancy rate. Average age of patients, IVF-ICSI technique. Results: Mean age of the patients 33,41. IVF technique: 66.4% ICSI 73 patients: 37 patients 33.6%. Pregnancy: If pregnancy: 57.3% No pregnancy: 42.7%. Tasa of oocytes in metaphase II: A Media 7.5. Conclusion: The pregnancy rate coincides with the center's results (50-60%), the reach from 7 mature oocytes. The average rate was 39.2% blastulation.