 |
|
Embryo culture during the five following days after fertilization allows us to carry out a better selection of embryos to be transferred to the uterus. For example, sometimes embryo division stops on day 3 after fertilization and, therefore, these embryos are not suitable to be transferred to the uterus. By using embryo culture to blastocyst stage we ensure that the embryos transferred are viable and have successfully overcome a potential block during their development, leading to higher embryo implantation and pregnancy rates.
An elevated number of embryos are required, because not all of them arrive to be Blastocysts, and not of all them have good quality. So, if we have very few embryos, the embryo transfer must be done in day 2 or 3.
16-20 hours embryo, after fecundation (Day 1)
Four cells embryo. 48 hours after fecundation (Day 2)
Eightr cells embryo. 72 hours after fecundation (Day 3)
80 hours embryo compacting (Day 3)
120 hours embryo. Blastocyst (Day 5)