Embryo
Following fertilization an embryo develops from the egg cell. Already on the second day after egg cell removal it is composed of 2 to 6 cells. The subsequent hours and days of development are decisive for the success of the treatment. At this stage there are constant improvements in the embryo culture. Incubators are constantly being improved, so as to provide the perfect surroundings for the embryo, so as to resemble the conditions found in the body of the woman. The culture medium, in which the embryos are situated, is also enhanced.
Nevertheless, embryos show large variations across different couples and occasionally even the embryos from the same couple and treatment differ greatly from each other.