It is a technique in which an embryo is developed in the laboratory for 4-6 days after fertilization before being placed in the womb. The embryo gains many cells as a result of being developed for so many days. The embryo developed for 4-6 days are much more advanced than the ones developed for just three days. These embryos are called blastocysts.
The embryo which survives for 4-6 days is more likely to produce fruitful results. This enables embryologists to select from the more advanced embryos with better potential for implantation.
The biggest advantage of the Blastocyst Culture and Transfer method is that it significantly reduces the risk of multiple pregnancies. Also, the pregnancy and implantation success rate is higher in this technique because it is easy to determine the robust embryos after developing for 4-6 days, hence, only the competent embryo is transferred to the uterus.
Blastocyst grading or quality is determined by evaluating the outer ring of cells, known as the trophectoderm or trophoblastic cells, that will eventually form the placenta; the inner cell mass or ICM, which is made up of the stem cells that the baby will develop from.
Scoring of blastocysts is an imperfect science, and some very nice-looking blastocysts do not necessarily produce a pregnancy. However, the basic rule of thumb is that the best embryos make it to the blastocyst stage, and therefore have a greater chance statistically of producing an ongoing pregnancy than a lesser quality one.
With blastocyst implantation, unlike a day three embryo which must continue to develop following embryo transfer, a transferred blastocyst will implant much more quickly. Scientific evidence shows that blastocyst transfer success rates are higher than the transfer of day three embryos.
Blastocyst Transfer Procedure
The final stage of the process is the transfer of the embryo to the womb. A catheter holding the embryo is gently inserted into the cervical channel and into the uterine cavity guided by ultrasound. The catheter is then removed and checked to make sure the embryo has been transferred. After the transfer, you can return to normal with the embryo quite safe within the uterus. Following a blastocyst embryo transfer, a pregnancy test is usually arranged twelve days later. During this time, it is best to avoid strenuous activity and heavy lifting.
Studies suggest that pregnancy rates improve if the embryos are left to develop to their blastocyst stage.