Embryo development until blastocyst stage with and without renewal of single medium on day 3.

OBJECTIVE: This study aimed to assess the effects of using a single culture medium not renewed on day 3 on the development of the embryo up to the blastocyst stage. METHODS: The study was carried out in the Assisted Reproduction Laboratory of Clínica Miraflores in the period ranging from April to December of 2016. The study included 589 human embryos obtained from 82 couples submitted to IVF/ICSI with donor oocytes. The couples were randomly divided into two groups: group 1 (medium renewed on day 3) and group 2 (medium not renewed on day 3). RESULTS: Significant differences in pregnancy rates, implantation rates, and blastocyst formation were not observed. CONCLUSION: No statistically significant difference was found between the groups with respect to the analyzed parameters. However, a non-significant trend was observed in favor of the group without medium renewal for clinical pregnancy and positive pregnancy rates (ß-hCG).