www.dunyaivf.c...
No. I think both embryo transfers has both pros and cons ( harms and benefits) and I think the pro`s of the day 5 embryo transfer outweighs the pro`s of the day 3 embryo transfer.
Let`s look at what are those pros and cons for both embryo transfer. First of all, the uterine environment is more synchronized with a Day 5 vs a Day 3 embryo. It is thought that the uterine environment, may not be a better environment for a Day 3 embryo.
That’s because it takes about 4 days for the embryo to make it to the uterus. On Day 3, the embryo is still making its way through the Fallopian tube so this environment may be better suited.By Day 5, the embryo is in the uterus. And this synchronization between embryo and the uterus may be an important factor for success. Some believe that Day 3 embryos may experience stress in this environment (Glujovsky & Farquhar, 2016).
Secondly, Day 3 embryos have a higher aneuploidy rate so some may drop out, or arrest/stop growing, by going to Day 5 (embryo`s elimination, natural selection).
Pros/cons of Day 3 or Day 5 embryo transfer
Day 3 transfer (ASRM, 2018)
• Higher number of embryos available for transfer/freezing
• Potentially higher cumulative rates (controversial)
• Less cost to transfer than to start a new cycle
• Lower implantation/pregnancy rates
For Day 5 transfer (ASRM, 2018):
• Higher implantation/pregnancy rates
• Potentially higher cumulative rates (controversial)
• Potential for choosing best quality embryo for single embryo transfer
• Better synchronization with uterus
• Higher chance of cancelled transfer
• Fewer embryos available for transfer/freezing
The ASRM reviewed the data in their committee opinion (ASRM, 2018):
• In good prognosis patients - Day 5 transfers have higher success
• In poor prognosis patients this is less clear
• Less available embryos for freeze/transfer on Day 5
According to the SART (The Society for Assisted Reproductive Technology
• Day 5 transfers had a higher live birth rate vs Day 3 (37.9% vs 28.8%)
• Day 5 had a higher cumulative pregnancy (60.6% vs 47.7%)
• Day 5 had a higher ongoing pregnancy rate compared to Day 3 (68.4% vs 59.4%)
• Slightly lower odds of miscarriage with Day 5 transfers
• Slightly increased odds of delivery before 37 weeks with Day 5 transfers
• No differences in ectopic pregnancies or in birth weight,
(Holden, et al., 2018)
According to some reserachers the main advantage for Day 3 transfers is a psychological one. For some patients, to go through the IVF procedure and to come out without anything to transfer on day 5 is devastating and some would prefer that their body is the deciding factor and not the lab for this. The truth is we don’t know what will happen in your specific situation, and the science is far from conclusive (Haad et al; 2019)
NOTE :A big problem with all this is the variability between studies: different culture media, different freezing methods, different number of embryos transferred, some only looked at fresh transfers, etc. This makes it hard to make conclusions, but overall it seems that Day 5 is superior to Day 3.It is really important that each IVF laboratory finds their own successful protocols. For me, as an embryologist, overall it seems that Day 5 is superior to day 3.
26 авг 2024
