This is a very good question. It is dependable on each lab so I think it is based on the experience of the embryologist that carries out the process of the biopsy which is the aspiration of the sample from the embryo. It is a very technical procedure that has to be carried out by an experienced embryologist. My answer to whether this process damages the embryos is that it depends on the experience of the embryologist. The second part is that we don’t know what the biopsy does in the embryos. So far all the meta analysis and papers that are out there are showing there are no major differences between the babies that have been born throughout this procedure and conventional IVF. However we really don’t know how this might affect an embryo. So all the babies born since 1991, are normal or at least normal in them having the same abnormalities as IVF babies from conventional IVF but we really don’t know what this process might do in an embryo.
Like all surgical techniques, embryo biopsy has to be done by very skilled individuals, in this case by embryologists. They need to be trained in either animal material or material that cannot be used for clinical activities. They need intensive training; they need intensive quality control. Once the learning curve is passed, they can apply for live material.
Under these circumstances, the risk of damaging an embryo is minimal, below 1%. This will not affect the potential of the embryo to implant.
So far, all the information that we have about the safety of PGS when it is done on day 5 suggests that at least regarding the implantation rates, there are no drawbacks if you take those 3-5 cells we usually take during the biopsy.
It’s true that when PGS was initially done on day 3, the information we had suggested as well it was a safe procedure, we later found out that was not true. The embryos that were biopsied on day 3 showed a 40% lower implantation rate than those that were not biopsied. Taking into account that the cells that we are now studying are the cells that are coming from a structure that is going to be the placenta, which means we don’t touch the inner cell mass, which is going to be the proper embryo later. Therefore, I feel that this kind of biopsy is much safer.
There was one study that compared the implantation rates of the embryos, with doing the biopsy or without doing the biopsy. The result of that study suggested that the embryos were implanted at the same rate. There were no differences.
It’s true that nowadays, the amount of information that we have is not that much because PGS is not such old technology. Probably, we now can confirm that for these 15-20 years that it has been done, it is a safe procedure, and the babies that are born after PGS do not show any higher risk of any kind of health issues.
I really think that PGS done on day 5 is a safe procedure for the embryos, and it does not have any mid-, or long-term side effects.
