One of the decisions between the two regarding IVF is when to transfer the embryo. Should this early-stage embryo be transferred or developed further into a blastocyst? The advantages of both procedures outweigh their differences. However, these differences highly influence the outcome of the IVF cycle. IVF Doctors explain to patients the critical differences between cleavage stage and blastocyst transfer.
What is Embryo Transfer in IVF?
In IVF, after a fertilized egg is formed by sperm in the lab, it is referred to as an embryo. Traditionally, the embryo is transferred to the woman’s uterus on Day 2 or Day 3 after fertilization. The embryo at this stage has approximately 4-8 cells, not very much farther along from their initial cell division and formation.
What is Blastocyst Transfer?
It is at a more developed stage in which the blastocyst forms around Day 5 or Day 6 post-fertilization. The embryo is divided into approximately 100-120 cells, making up two main parts of the embryo– the inner cell mass that will eventually be the fetus and the trophoblast that will form the placenta.
Key Differences Between cleavage stage and Blastocyst Transfer
Developmental Stage
Cleavage stage Transfer: This is typically performed earlier, on Day 2 or 3 following fertilization when the embryo has started to divide into a few cells.
Blastocyst Transfer: It is normally undertaken later on, on Days 5 or 6 of development, after the embryo has structured itself into a defined pattern of types.
Success Rates
Cleavage stage Transfer: The more traditional procedure in use can lead to pregnancies if transferred but implantation rates are always poorer than those for blastocysts.
Blastocyst Transfer: In research, which includes data from Dr. Pratik Tambe’s clinic, blastocysts, have been proven to have a greater likelihood of implantation in uterine linings.
Single Embryo Transfer
Cleavage stage Transfer: Generally, most doctors insist on transferring more than one early-stage embryo for better chances of implantation. This can lead to greater chances of multiple pregnancies.
Blastocyst Stage: Due to the enhanced implantation capacity, single embryo transfer might be sufficient with the transfer of the blastocyst and, accordingly, multiple pregnancies are less probable.
Who can benefit from Blastocyst Transfer?
Younger Patients: This is especially the case in more youthful patients who have a greater ovarian reserve; they have a higher chance of producing potentially high-quality embryos that could subsequently evolve into blastocysts.
IVF Cycles with Multiple Embryos: Using blastocyst culture, those who are producing several embryos in an IVF cycle will be offered the opportunity to have their embryologists choose the best blastocysts to transfer.
Benefits of Blastocyst Transfer
Greater In Vivo Implantation Rates: A blastocyst is more developed than any of the other forms described so far. Therefore, it has a likelihood of being implanted in the uterus.
Reduced Multiple Pregnancies: The occurrence of multiple pregnancies in the form of twins as well as triplets very minimal since sometimes a single blastocyst is enough for the procedure.
Better Selection of Embryos: Embryologists can now observe how the embryos develop and select those that have a high success rate by waiting until the stage of the blastocyst.
When Embryo Transfer is a Better Alternative?
However, not every patient is a good candidate for blastocyst transfer. According to Dr. Pratik Tambe, some patients are better selected for embryo transfer in the following conditions:
Older Patients: Older women or those with a diminished ovarian reserve may not produce enough embryos to wait until the blastocyst stage.
Limited Embryos: If only one or two embryos are available, then transferring them at the early stages might be the best option since not all embryos survive until the blastocyst stage.
Conclusion
The decision on the transfer of an embryo or a blastocyst depends solely on the age, ovarian reserve, and the number of embryos in an IVF cycle. Therefore, early-stage embryo transfer may not be avoided in all patients, though the benefit of single embryo transfer and the offer of higher success rates characterize the approach of blastocyst transfer.
If you’re considering IVF, come to decide which one of these may be the best suited for you with Dr. Pratik Tambe at ivfdoctors.in. Only once you understand the differences between these techniques you might feel more confident and informed in this journey of fertility.
FAQs
A cleavage stage embryo and a blastocyst: What’s the difference?
A cleavage stage embryo is in the early development days (Days 2 and 3), while a blastocyst is an advanced structure at Days 5 and 6 that contains more cells and is suitable for implantation.
What is the success rate of embryo or blastocyst transfer?
Generally, there is a higher success with blastocyst transfer since the embryo has reached a better developmental state and has the chance to implant in the uterine environment better.
Why might a person choose an embryo transfer as opposed to a blastocyst transfer?
Many patients, particularly older patients and those who have few embryos remaining appreciate early-stage embryo transfers because not all embryos will survive the blastocyst stage.
Is every embryo likely to reach the blastocyst stage?
No, not every embryo will survive to the blastocyst stage. A patient’s embryo’s quality and that individual’s fertility factors dictate whether or not an embryo will develop into a blastocyst.
Is it better to reduce the risk of multiple pregnancies?
Blastocyst transfer reduces the risk of multiple pregnancies as compared to cleavage stage transfer.
