Eeva™ In Vitro Fertilization Technology Today
Embryologists typically assess embryo(s) under a microscope using a morphological grading scale to determine which embryo(s) to transfer back to the mother on either Day 3 (cleavage stage) or Day 5 (blastocyst).
Some clinics prefer to wait until Day 5 to transfer the embryo(s), potentially improving the probability of success through embryo self-selection. Studies have shown that transferring embryos at the blastocyst stage more than doubles the chance of a live birth when compared to Day 3 transfer for certain age groups.3,4
However, culturing embryos for two extra days outside the body is challenging and may have an increased risk of embryo arrest as well as long-term effects such as identical twins and epigenetic disorders.5 As a result, many clinicians prefer to transfer the embryo back into the mother as soon as possible, even though traditional embryo assessment techniques at such an early stage limit their ability to consistently select the most viable embryo.
3. Papanikolaou et al. New England Journal of Medicine. 1139-1146.2006.
4. Papanikolaou et al. Human Reproduction. 20(11):3198-3202.2005.
5. Katari, Sunita et al. Human Molecular Genetics. 3769-3778. 2009.