No. It would be possible if birth defects were caused by a single cause, but there are many different causes and it is not possible to detect them all at once. There are also abnormalities that are not based on genetic causes.
So, what should we understand when we say genetic analysis in IVF?
The best way to explain this is to divide the couples into couples with genetic problems and couples without. The practices we hear in the media as “increasing IVF success” are actually about couples who don’t have any genetic problems.
Why is a genetic analysis performed for the couple who have no genetic problems?
To increase the chances of pregnancy or to help couples who are unable to conceive despite repeated IVF applications. So it is not routine practice. The frequency of application also differs greatly from country to country. While it is freely used in the United States, which many do, in France it may only be done with the permission of the relevant council if there is a genetic disease in the family. The situation is the same in England. Italy, on the other hand, banned it completely for non-medical reasons, being a Catholic country. It was forbidden even if the baby to be born was sick. Later this ban was lifted by a court decision, now it is possible if there is a known illness in the family.
There is no restriction other than gender selection in our country.
I will ask how to increase the success of IVF, but first can you give a brief information about the diseases to be done?
As you know, some families have diseases that are passed down from generation to generation. Some are dominant. If the mother or father is sick, the baby will be born sick with a 50% chance. Some are recessive, which is common in consanguineous marriages. Both parents must be carriers for the baby to be sick. Thalassemia, which is common in our country, and SMA, which we hear more often due to new treatment methods, are such diseases, for example. These families can give birth to a baby who does not have these diseases in the family by applying for IVF.
How do genetic applications increase success in IVF?
The most common reason for not getting pregnant every month in normal life or with in vitro fertilization is that not every embryo has a normal chromosome structure. This is actually a different situation from gene diseases that are passed down from generation to generation. It means that the 46 chromosomes we have are not normal in number and order. It mainly has to do with the age of the woman, because as the woman gets older, the chromosome structure of the eggs deteriorates. Although the chance of a good quality embryo attaching at a young age is about 40%, it decreases with age. For example, at the age of 42, one in 7-8 eggs is intact. However, if we can demonstrate that the chromosomes are normal by performing PGT-A before transferring the embryo, the chance of attachment increases to 70%.
So it doesn’t guarantee fertilization?
No, it is not guaranteed. However, for a woman of advanced age, it at least prevents an unnecessary transfer. It also halves the risk of miscarriage. It certainly shortens the time to achieve a healthy pregnancy.
So why isn’t it used more often?
Because it causes us to lose some embryos. If there are enough embryos, this is acceptable. However, if you have a small number of embryos, you may not want to risk losing them. There are 2 reasons for losing an embryo. The first is the biopsy procedure. As a result, a piece of the embryo is removed. With a good embryologist we can say that this risk is very low. The second is that the lab result does not reflect the truth. It’s just a matter of technical reasons. It even happens that the transferred embryos with an abnormal chromosome structure result in a healthy birth.
As a result, PGT-A is a decision to be made after discussing all the details with the couple, depending on the couple’s characteristics. If there is any discrepancy in the pair’s karyotype analysis, it should definitely be done. I recommend it to avoid many unnecessary transfers and miscarriages in women with an abundance of embryos in old age. It should be recommended in people with few embryos at an advanced age, when there is a risk of disappointment after failed transfers and the abort of the trials. If women whose ovaries are at risk from surgery or various treatments want to preserve embryos for the future, it makes much more sense to keep the embryos that have been proven to be healthy after PGT-A. Even if there isn’t enough scientific evidence for those who’ve had repeated IVF attempts, I’d recommend at least understanding what’s going on.