Definition - What does Day 3 Embryo Transfer mean?
An embryo transfer is a procedure of transferring embryos back into the endometrial cavity (uterus) of a patient during an in vitro fertilization (IVF) cycle. For a 3-day embryo transfer, the embryo is transferred back into the uterus on the third day after fertilization, when the developing embryo is in the cleavage stage (before the blastocyst stage).
FertilitySmarts explains Day 3 Embryo Transfer
During the early days of IVF when it was not successful to keep embryos alive for very long outside of the human body, all embryo transfers took place immediately after fertilization since fertilization was a huge barrier to reproductive success. The procedure was typically performed on the second or third day after egg retrieval.
As scientific advancements continued to be made in embryo culture, embryos were developing well over three days after egg retrieval. Now, many IVF transfers are done upon the 5th day after egg retrieval, when embryos have reached the blastocyst stage since the blastocyst stage of development is an important benchmark and if present leads to a higher implantation potential.
Today, 3-day embryo transfers are still performed for couples that do not have a large number of embryos to compare and evaluate or that do not have successful artificial culture development. Day 3 transfers are often not as successful as day 5 transfers but that is sometimes because the fertility of a woman that does not stimulate well on a traditional stimulation protocol or that has poor embryo development in the laboratory is reduced compared to the fertility of a woman that stimulates well and has successful blastocyst development.
- Cleavage stage versus blastocyst stage embryo transfer in assisted reproductive technology. (2016).
- When only one embryo is available, is it better to transfer on Day 3 or to grow on?. (2019).
- Day 3 embryo transfer versus day 5 blastocyst transfers: A prospective randomized controlled trial. (2017).