Choosing the most suitable day for embryo transfer is crucial in IVF treatment. The transfer day is determined by considering embryo quality, the couple's condition, and the treatment strategy. So, Is it a day 3 embryo or a day 5 embryo? is it more advantageous?
General Information on Embryo Transfer
If the number of embryos is low (1–2 embryos), there may not be a significant difference in success rate between early transfer (day 2 or 3) and day 5 transfer.
Day 5 embryos (blastocysts), These are embryos that have progressed to a more advanced stage. Reaching this stage is like a selection process; it allows high-quality embryos to reveal themselves.
Embryos transferred on the same day can continue to divide inside the uterus and reach the blastocyst stage.
Why are blastocysts (day 5 embryos) important?
Day 5 embryos, or blastocysts, are stronger embryos that have been able to continue their development.
If preimplantation genetic testing (PGT) is to be performed, the embryo must have reached the blastocyst stage.
In couples with multiple embryos, blastocyst transfer offers the chance to select the best embryo.
If pregnancy has not been achieved despite several previous day 3 embryo transfers, a day 5 transfer can be attempted.
Factors Affecting Blastocyst Development
Chromosome structure: It is the most crucial factor in terms of embryo health.
Sperm quality: It plays a critical role in blastocyst development.
Egg quality: Although it is more decisive in the early stages, it affects overall development.
👉 If good-looking embryos fail to reach the blastocyst stage, this may indicate genetic problems and detailed sperm tests may be necessary.
When are day 2 and day 4 transfers preferred?
Transfer on day 2: In couples with a low embryo count, it may be preferable to implant the embryo in the uterus without further delay in the laboratory. The understanding that "the best laboratory is the mother's womb" applies here.
Day 4 transfer: If there are many embryos, differences in quality become more apparent at this stage. After evaluating the development of the embryos, a decision can be made regarding transfer.
✨ Result: Double Special Decision
There is no single correct way to determine the ideal day for embryo transfer. The decision should be made considering the couple's age, the number of embryos, their previous attempts, and laboratory conditions.
👉 Treatment is different for every couple; therefore “"Double special planning"” It brings the highest success rate in IVF.
