C) Keep in mind the importance of Embryo Preimplantation Genetic Testing (PGT)
PGT-A, also known as Preimplantation Genetic Testing for Aneuploid, is a procedure that helps identify abnormal chromosome numbers.
When sperm and eggs combine, they bring together two chromosomes. An egg has 23 X chromosomes, while a sperm can have either 23 X or 23 Y chromosomes. This combination determines the chromosomal complement of the embryo, which is considered normal when it is 46 XX or 46 XY. Anything other than that is considered abnormal, such as an extra copy of chromosome 21, which leads to Down syndrome.
Embryonic chromosome abnormalities or aneuploidy are the leading cause of miscarriage.
PGT-A does not improve the quality of embryos, but it does provide information about which embryos have a normal number of chromosomes.
One of the significant advantages of PGT is that it reduces the need for multiple embryo transfers and lowers the risk of miscarriages, ultimately helping couples achieve pregnancy faster.
In Japan, PGT is only offered to patients who have experienced two miscarriages, recurrent implantation failure or if one of the partners has a chromosomal structural abnormality.
Conversely, in Taiwan, PGT can be available to those undergoing their first IVF.
There are differing opinions on the necessity of PGT for the initial IVF attempt, but if you want to determine whether the embryos have Down syndrome, PGT-A becomes undoubtedly required.
There is also the fact to consider that in Taiwan you have the freedom to decide whether or not to undergo PGT, whereas in Japan, it is not available during the first IVF cycle.
How is PGT performed?
PGT involves taking a biopsy of the blastocyst stage embryo📝 . This biopsy is then sent for genetic testing to examine the chromosomal complement of the embryo. The results can indicate whether the embryo is normal or abnormal. After the biopsy, the embryos are frozen and a normal embryo is chosen for a future transfer.
📝Blastocyst stage embryo:
After 5-6 days of fertilization and cell division, an embryo develops into a blastocyst. However, not all embryos are able to reach this stage. If genetic information in the embryo is not correct, sometimes the development may halt.
The blastocyst stage is considered the most suitable for implantation in the uterus, as it has the highest potential for successful implantation, and similar to natural conception where the embryo reaches the uterus at this stage.
It is highly recommended for women over 40 years old to do PGT
As you get older, the chances of having aneuploid eggs increase.
35-37 years old: 1 out of 2 blastocysts is chromosomally normal
38-40 years old: 1 out of 3 blastocysts is chromosomally normal
41 years old: 1 out of 5 blastocysts is chromosomally normal
42 years old: 1 out of 6 blastocysts is chromosomally normal
43 years old: 1 out of 7 blastocysts is chromosomally normal
(It is suggested that women over the age of 43 consider utilizing donor eggs.)
Reference:https://en.e-stork.com.tw/article/view/30
There are various types of PGT available for different purposes:
PGT-A
Detecting abnormalities in the number of chromosomes.
Also called PGS (Preimplantation Genetic Screening)
PGT-M
Detecting monogenetic or single gene disorders.
For instance, if both partners carry cystic fibrosis or if you carry the BRCA gene and wish to exclude it, PGT-M can be utilized.
Also called PGD (Preimplantation Genetic Diagnosis)
PGT-SR
Discovering translocations, which occur when chromosomes swap places.