[Gamete laboratory. Determining factors of success in in-vitro fertilization]

The objective was to evaluate the gamete laboratory parameters that can to determine the possibility of achieving pregnancy in in vitro fertilization (IVF). A prospective study was carried in 196 patients undergone to conventional and oocyte donation IVF. After the evaluation of oocytes, embryos and the pregnancies was established that postmature oocytes were more frequently retrieved from patients that did not get pregnant. A good embryo morphology and principally the transfer of 4-cell embryos are common events in IVF. However, there were not significant difference in embryo parameters, number of blastomeres and embryo quality, between pregnant and not pregnant patients. In conclusion, it appear that bad oocyte quality has a negative effect over the possibility of achieving pregnancy. The number of blastomeres and embryo quality were not predictive of the possibility to get pregnant.