A new study has found that embryos which are classified as abnormal have the ability to self-repair into a healthy embryo
The scientific research was announced at the congress of the European Society of Human Reproduction and Embryology (ESHRE), held in Vienna at the end of June.
The study, which included British patients, was made possible by Embryoscope, an embryo incubator that has a video camera attached to film the development of embryos and was developed by the Institut Marques. The institute said it has proven that embryos which have reabsorbed their own cells and then kept on dividing until they reach blastocyst stage on day five or six have the same implantation, evolutive pregnancy and healthy born child rates.
In IVF treatment, embryos are classified according to guidelines based on their appearance and the way they develop. In this way, the ones that are considered to have the best prognosis to implant and continue evolving are transferred to the patient.
Some embryos suddenly make their own cells disappear
Nowadays, it is considered optimal for an embryo to have four cells on the second day of life and eight cells on the third. But some embryos suddenly on the second or third day make one of their own cells disappear – changing the number of cells from four to three. Afterwards, they keep on dividing as if nothing has happened.
Sergi Novo, biologist at Institut Marques said: “To date this phenomenon, known as reverse cleavage, was considered a sign of bad prognosis and, because of this, the evaluation of the embryo was considerably reduced.”
With the currently established rules, embryos that do not follow the guidelines are considered to have less chance of developing. Institut Marques is now reassessing these guidelines to show that many of the standard criteria are wrong.
“Finding out that the human being, in its second or third day of life is already capable of determining that one of its cells has been altered and then removing it so it can keep growing in a healthy way is an amazing thing,” manager of Institut Marques, Dr Marisa López-Teijón.
More than 300 embryos were observed completely absorbing one its own cells
“This proves that life doesn’t consist of being born perfect, but in being able to correct one’s defects. Not only do those who seem perfect manage to live, but also those who have fought to be perfect,” she added.
For this reason, Institut Marques has carried out a retrospective study of the development video of 23,340 embryos, from their fertilisation to the moment they reach the blastocyst stage.
The institute discovered that in 303 of the studied embryos, the presence of complete absorption of one of its cells was observed
These embryos showed a slight decrease in the proportion that reached the blastocyst stage, however, the rate of healthy born babies remained the same. Therefore, the embryos that can overcome this repair activity have the same reproductive potential.