Prolonged Cultivation

Prolonged embryo cultivation is one of the methods promoting the pregnancy success rate. At present, standard cultivation takes 72 hours (3 days). Prolonged cultivation takes between 120 and 144 hours (5 or 6 days). After 120 hours, ideally developing embryos reach the blastocyst stage and blastocyst transfer increases the chances of impregnation.

Prolonged cultivation allows to select embryos with the highest development potential that are developing consistently and survive the 4 to 8-cell stage, in which development halts most commonly. In addition, later embryo transfer is more consistent with the natural course of conception when the embryo reaches the uterus 5 to 6 days after fertilisation.