Day 5 vs. Day 3 Embryo Transfer

Day 5 embryo transfer vs. Day 3 embryo transfer vs. “Sorry, no transfer; all of your embryos arrested”.

Has this ever happened to you ? Your entire IVF/ICSI cycle “wasted” because you made few embryos that did not survive in the laboratory to become blastocysts (day 5 embryos) so you did not have an embryo transfer at all ? I have seen several couples who have had this happen to them, and feel our patients need to have this issue addressed.

For many decades, women have conceived and delivered healthy children after embryos were transferred on day 3 after egg retrieval. As laboratory and culture systems improved, it became possible to culture embryos in the laboratory for a couple of more days. Not all embryos can survive in a laboratory this long, although they can result in normal pregnancies if transferred on day 3 of laboratory development. The advantage of a day 5 or blastocyst transfer is a higher implantation and pregnancy rate per embryo transferred since less “strong” embryos will not survive, and therefore the scientists and physicians are stressing all of the embryos to detect the best quality embryos and also decrease the chance of multiples such as twins, by transferring fewer embryos. This method of embryo selection is most helpful in women with so many embryos to choose from that the embryologists can’t estimate which are the strongest on day 3 after retrieval, so they observe their development for a few more days. This method does not improve the chance of pregnancy from any individual embryo, it only finds the strongest that survive. If a patient only has 2 or 3 embryos, prolonged culture does not improve their quality, and the best chance for pregnancy is therefore an earlier transfer on day 3.

Also, some couples have been told that normal embryos will develop to blastocysts in the lab, and if all of their embryos died it was “meant to be” implying that their embryos were not normal and they either would not conceive at all or would miscarry an abnormal fetus; a cheaper way of assessing the genetic health of an embryo. There is absolutely no scientific evidence for these opinions.

At IRMS, we do both ay 3 and day 5 embryo transfers. Our recommendations are individualized for each couple and not a “one size fits all” approach, as we attempt to attain the highest chance for a term, healthy live birth for each couple.

Bottom line:

1. Transferring 1 day 5 embryo (blastocyst) has almost the same pregnancy rate as transferring 2 day 3 embryos, and almost no chance of twins (compared to a 20% chance of twins transferring 2 day 3 embryos.
2. Transferring 2 day 5 embryos has a higher pregnancy rates and a 30 to 40 % chance of twins
3. Some patients are better served having a day 3 embryo transfer.

I recommend all couples have the discussion with their Doctor about the transfer philosophy at their program, long before the sad phone call on day 5 that their transfer is cancelled due to the “arrest” of all of their embryos.


Margaret Graf Garrisi, M.D.Margaret Graf Garrisi, M.D., joined the Institute for Reproductive Medicine and Science in 1999. Dr. Garrisi brings more than 20 years of experience and achievement in Obstetrics, Gynecology and Infertility to her position as Medical Director of Assisted Reproduction in the Division of Reproductive Endocrinology.

Dr. Garrisi fills many roles at IRMS and in the community. She is a clinical specialist with expertise in the diagnosis and surgical treatment of fibroids, uterine polyps, and endometriosis. Dr. Garrisi also lectures to physician groups and the public about topics related to reproductive health and infertility.

Speak Your Mind