Undergoing the In Vitro Fertilisation (IVF) treatment can be quite daunting for couples. It is a long and laborious treatment, and appointments are time-bound. The medication is strong and can have harsh side effects. A wise remark by someone regarding IVF went like this – “You better get used to the idea of needles and stop flinching every time you see one”.
Blastocyst transfer is a technique in which the embryo is allowed to develop into a blastocyst before it is transferred to the mother’s uterus. This technique has shown excellent results and has been very successful. The Blastocyst transfer is now being used more commonly for IVF treatment.
The blastocyst transfer allows the embryologist to select the best quality embryo for the IVF procedure. The quality of the embryo is essential in determining the success of the pregnancy. Some embryos do not become blastocysts. By monitoring the embryo development and growth over the 5 to 6 day period, it ensures that the embryo selected for the IVF procedure is healthy and has a strong survival chance.
In the blastocyst transfer, fewer embryos are transferred to the uterus, and this reduces the chances of multiple pregnancies. Patients usually request for multiple embryos to be transferred to the uterus in the hope of increasing the probability of a successful pregnancy. With the blastocyst transfer, the success rate is much higher; hence, usually, only one or two blastocysts are transferred to the uterus. 25% of the times when two embryos are transferred them both implant. The dual blastocyst transfers result in multiple pregnancies as both of them begin to develop.
In a natural pregnancy, the egg is fertilised in the fallopian tubes. This embryo takes over 3 days to travel to the uterus where it hatches and begins implantation by the 6th day. The blastocyst transfer follows the timings of the natural process quite closely. By transferring the egg when it is 5 or 6 days old, the uterus is ready for it, and the embryo almost immediately starts attaching itself to the uterus wall.
The Blastocyst begins to hatch in the lab even before it is transferred to the uterus. Hatching is an integral part of the success of the IVF procedure. If an embryo does not start hatching by the 6th day, a technique called assisted hatching can be used. The blastocyst transfer allows the doctors to monitor and assist in the hatching if required. This improves the chances of getting pregnant. This is a very great advantage of the Blastocyst transfer and has helped to really improve the success of the IVF procedure.
Some embryos arrest before the 5th day. Many times in the 2-3 day transfer it was found the embryo has arrested and the IVF procedure failed due to this. The blastocyst transfer eliminates the possibility of transferring embryos that will arrest before day 5 and ensures a higher embryo survival rate.
During the development of the blastocyst, it is easy to sift out the embryos that have any abnormalities. Embryos with chromosomal abnormalities usually do not reach the blastocyst stage. These embryos arrest before the 5th day.
It is easier to perform preimplantation genetic diagnosis (PGD) on a blastocyst as more cells are available for extraction and testing. The PGD tests help to remove the defective embryos and ensure that a good embryo without any genetic defects is transferred during the IVF procedure.
When an embryo has a defect, it usually stops growing after a while. In cases where defective embryos have been transferred in the 2-3 transfer procedure, even if these embryos do implant, it ends up in a miscarriage. Therefore the Blastocyst transfer reduces the rate of early miscarriages as well.
Almost 40% of the embryos do not become blastocysts; these could be abnormal embryos or defective embryos or just weak embryos which have a low likelihood of survival. The blastocyst transfer has enabled couples to have healthier babies with fewer birth defects and abnormalities.
With Blastocyst, we have also seen a marked increase in the success rate of IVF treatment.
A blastocyst is now the most popular technique employed to fertilise the egg in the IVF Treatment, and the cost of the procedure is included in the IVF treatment cost.