In this webinar, Rocío López, Embryologist at PreGen (Vistahermosa UR), Alicante, Spain, discussed egg banking from her perspective as an embryologist.
There are two ways to match the donor with the recipient. The first way is phenotypical matching characteristics such as eye colour, skin colour, skin and hair high colour are matched. The other way is gene matching. We perform a blood test of the egg donor and the partner of the recipient, in this way, we can know if they have some genetic diseases, and it’s the same for the partner of the recipient, and we do the matching and making sure that both of them are not carrying the same pathology.
There are two types of panels. The basic panel where we study 50 diseases, and the other one is a much bigger panel where we can study more diseases. In our clinic, we don’t use GeneXMatch, so it’s hard to advise on that.
The quality of the oocytes decreases at 38-40 years old. The survival rate is not affected however, the quality, genetics, morphology of the oocytes will be affected. That’s why it’s better to preserve fertility earlier at around 32 and until 35-36 years old.
In Spain, we have a limit of the number of times the donor can donate, it’s a maximum of 6 donations. If you go for a fresh egg donation, and you transfer either 1 or 2 embryos, but you have some surplus and let’s say, it’s positive, and if you keep vitrified embryos, you can use these embryos in the future.
If both transfers are positive, you get two babies, of course, I guess that you mean that both children to be brothers or sisters we can do that of course, but we can never guarantee that we will have surplus embryos to freeze, in case, we don’t have embryos to freeze, then we can try to ask the donor if in the future she will be able to donate. That’s more or less what we do nowadays, it’s always important to remark that according to Spanish law, there is a maximum time that a donor can donate, which is a maximum of six times, we also need to take that into account. However, as soon as the donor can donate, we can use the same donor.
We only use Fenomatch. Apart from using Fenomatch, which is a tool that minimizes the risk of human error when selecting the donor, we also use 3 filters, like a genetic filter, biometric filter, to find the best donor that will match you.
The maximum percentage will be the best option for you. We also perform psychological screening of the donor, we also screen the donors with the six most common autosomal recessive diseases such us, fragile X syndrome, Cystic fibrosis (CF), we also perform a karyotype. We don’t use GeneXMatch or Ovomatch, we just use Fenomatch, and we ask the recipient to do a selfie with no makeup, no filter, no glasses, and we will use this picture, upload it on the software, and we will get a result.
We usually need around 8-10 mature eggs to have good preservation from the patient. That will depend on the patient’s ovarian reserve and age. It can be one or two cycles. For us, a good number will be between 8-10 eggs.