The Blastocyst Embryo transfer of the fertilized embryo to a female uterus is one of the important processes in IVF. Blastocyst or embryo is called when an egg is fertilized. Various questions can run through your mind if you are undergoing the IVF process for the first time. It is very natural. You might also be thinking about the procedure and the embryo transfer.
Most people don’t understand the term they will hear from their IVF expert during the process. So, to help you, we have brought the round-up of the top 10 things you need to know about blastocysts – based on the most trusted research.
What is Blastocyst?
A blastocyst is an embryo developed for five to six days after fertilization. It consists of cells forming the trophectoderm that later develop into the placenta, the inner cell mass, and a central cavity filled with fluid or the blastocoel.
The early embryo was transferred on day three of the IVF cycle. But now, it is believed that better-developed embryos, which have reached the blastocyst stage, make an ongoing pregnancy successful.
How Blastocyst Develop?
On day five of fertilization, the blastocyst is formed. Zygote, a single-structure cell, is formed and undergoes a series of cell divisions. The cells are known as blastomeres during the cleavage stage. It undergoes mitosis and cytokinesis simultaneously. These blastomeres form a tight junction that leads to the deformation of the round shape and the formation of mulberry-shaped cluster cells called the morula.
Then the fluid inside the zygote leads to the formation of the blastocyst. As the fluid accumulates inside the zygote, it forms a blastocyst. It consists of two distinctive tissues: the outer trophoblast and inner cell mass.
A healthy blastocyst often begins hatching from its outer shell, called the zona pellucida, between day 5 to day seven after fertilization and is known as hatching. And then, the blastocyst undergoes implantation in the uterus.
Whether should Blastocyst Embryo Transfer is transferred on day three?
Yes, it can transfer, but if you want to get a better outcome, it is better to wait for day five because there are chances that the embryo may not make it to day five if the sperm is not of good quality. At the same time, waiting for day five is more viable for implantation and successful pregnancy. Numerous other studies point to the benefits of blastocyst formation and culture.
Advantages of Blastocyst Embryo Transfer for IVF?
Blastocyst makes the thing easy for implantation and getting successful pregnancy. It requires optimal laboratory conditions.
The Blastocyst Embryo Transfer implantation process begins about three days later after the formation of the blastocyst and hatching out of the embryonic shell. So, it increases the chance of getting a healthy blastocyst.
Also, transferring the embryo on day five to the uterus is more receptive to the arriving embryo because in natural conception also, it is at the same time.
Some couples require pre-implantation genetic screening (PGS) or pre-implantation genetic diagnosis (PGD). For them, blastocyst culture is required as embryo biopsy is recommended to be done in the blastocyst stage rather than on Day2/3 embryos.
Why do not all IVF Patient use Blastocyst?
Every patient is different and has a different problem. So, there can be many reasons for not using blastocyst for all IVF patients, such as their age, treatment choice, medical history, egg and sperm quality, or the clinic may feel it’s better to transfer a younger embryo.
Whether Blastocyst leads to more IVF pregnancy?
Researchers say that live birth rates after blastocyst embryo transfer are higher than early transfer. It significantly boosts clinical pregnancy and lives birth rates.
What are the Benefits of going with blastocyst?
Transferring the embryo on day 2 or 3 does not have the capacity to become a high-quality blastocyst and to make your pregnancy viable. We also do not have a method to determine which embryo will be viable for the long term and which are not.
But by culturing embryos to day 5, we have an option to choose the most competent embryos for transfer and can have high pregnancy success rate even with fewer embryos transferred. The risk of multiple pregnancies is also reduced through blastocyst.
Whether is there any drawback with blastocyst embryo transfers?
No, there is no drawback with blastocyst embryo transfers. It is best to get to day five to know the quality of the embryo. You can choose the best one to transfer and one or two good ones to freeze.
Many IVF patients often overlook the importance of freezing embryos. Freezing of embryos will be helpful for a second attempt. Frozen embryo transfer is successful as fresh ones, especially for those using blastocyst. Freezing of embryos is important because patients are generally in the age group where the implantation rate is slightly lower.
Who can Benefit from Blastocyst Culture?
A blastocyst is advised for the following patients:
- It can be beneficial for patients with multiple failed IVF.
Patients with a history of failed IVF with day 2 or 3 embryo transfer can yield more information related to embryo growth and help improve the pregnancy rate.
- To eliminate multiple pregnancies.
Blastocyst culture allows the possibility of transferring the single best embryo, thereby reducing the chance of multiple pregnancies.
Are there chances of getting twins in single Blastocyst Embryo Transfer?
There are chances of getting twins, even a single blastocyst transfer. Because it can easily split more easily than younger embryos, especially the good quality ones; however, it is not very common.