One of the key steps that human reproduction takes along its path is the formation of a blastocyst. Anyone who has undertaken fertility treatments, such as IVF, or those interested in the very early development of humans should know what a blastocyst is and how it forms. Below, leading fertility and IVF treatment expert at ivfdoctors.in, Dr. Pratik Tambe, explains the process of blastocyst formation and why it is such an important step along the road to conception.
What Is a Blastocyst?
A blastocyst is an early embryonic development that occurs at about 5–6 days after fertilization. At this stage, the fertilized egg has already undergone several divisions and morphed into a cylinder with two major components- an inner cell mass, which will give rise to the foetus, and the trophoblast, the layer of cells that will become part of the placenta.
How Is a Blastocyst Formed?
The formation of a blastocyst begins after the sperm has fertilized the egg. Here is how this process is possible:
Day 1: Fertilization
The fertilized egg, now a zygote, marks the very first stage of the development process. The subsequent developmental processes are as described below.
Days 2-3: Cleavage Stage
This Zygote now undergoes rapid cell division, a process known as cleavage. The single cell splits into two, then four cells, then eight cells, making what is referred to as a morula. The embryo now has roughly 16 cells.
Day 4: Transition from Morula to Blastocyst
Once the morula stage is over, cells begin to differentiate, and fluid filling starts appearing on one part of the cells which then defines the formation of a blastocoel. This marks the beginning formation of a blastocyst.
Days 5-6: Development of the Blastocyst
By the fifth or sixth day, the embryo is now a blastocyst. The trophoblast is now the outer layer while the inner cell mass is a fluid-filled blastocoele. On the fifth and sixth days, the blastocyst is ready for implantation into the uterine lining. There it will undergo more development.
Why is the Blastocyst relevant to IVF?
The formation of blastocysts is an important stage in the treatment procedure for IVF to achieve a successful pregnancy. According to Dr. Pratik Tambe, embryos at this stage have a chance of implanting better than they do at other stages of development.
That explains why many fertility centres, including ivfdoctors.in, use the transfer of blastocysts more often instead of transferring embryos at other stages during IVF.
Facts About Blastocyst Formation
When: The blastocyst develops around 5-6 days post-fertilization, which is the reason why most IVF cycles transplant embryos in this stage.
When developed to be the embryo, the blastocyst has an inner cell mass that would eventually develop into a foetus and a trophoblast that would develop into a placenta.
When implantation takes place: When it develops to be a blastocyst, the embryo is now prepared to attach itself to the wall of the uterus, on which it will depend to continue development.
Beneficial Success Rate: According to most scientific studies, the success rate of IVF for conception is greater in the case of transferring blastocysts. This is because, here at this stage, the embryo is very much matured and more possibilities of implantation are there.
IVF and Blastocyst Grading
Therefore, in an IVF clinic, like ivfdoctors.in, embryos are often graded according to their quality. This graded system helps the embryologist make a prudent decision to select healthy blastocysts for transfer that may have a better chance of implantation. The inner cell mass is strongly defined, and its layer of trophoblast is healthy and robust in a high-quality blastocyst.
It is the decisive morphological step in natural conception and IVF treatment as well. Thus, the explanation of this process is only educates the patient but also the practitioner. According to Dr. Pratik Tambe, knowing what a blastocyst looks like and its role in pregnancy could provide an even clearer view of the complex, sometimes fascinating processes involved in human reproduction.
You can schedule a consultation with Dr. Pratik Tambe at ivfdoctors.in if you have more questions or are considering IVF and learn about the next steps for your fertility treatment.
FAQs
What is a blastocyst?
A blastocyst is a stage of embryonic development developed 5–6 days post-fertilization. It has an inner cell mass that develops into a foetus and a trophoblast, which develops into the placenta.
Why would one regard the blastocyst stage as important when undertaking IVF?
In IVF, those embryos that progress to achieve the stage of the blastocyst are likely to implant in the uterine lining, which makes the stage quite crucial.
Can all embryos form a blastocyst?
All embryos do not reach maturity to become a blastocyst, but a pregnancy can likely occur once the embryo develops into a blastocyst.
How is a blastocyst selected for transfer in IVF?
Embryologists grade the blastocysts based on their quality, so that the transfer of the most excellent-quality blastocysts may increase the chances of implantation.
What happens next after the transfer of the blastocyst in IVF?
After the transfer, the transferred blastocyst might still hopefully implant in the uterine lining as it continues developing into an embryo and then into a foetus.
