Embryos have the capacity to self-repair from the second day of life

This revelatory discovery has shown that embryos that have reabsorbed some of their own cells and then continue to divide up to blastocyst have the same rate of implantation, of evolutionary pregnancy and of a healthy born child

There are embryos that in their second or third day of life absorb some of their own cells. For example, they go from four to three cells and then continue to divide, as if nothing had happened. Until now, this fact was considered abnormal, but a study carried out by Institut Marquès, international reference centre in assisted reproduction proves that, in this way, nature gets to self-repair.

This revelatory discovery has shown that embryos that have reabsorbed some of their own cells and then continue to divide up to blastocyst (the early stage of embryonic development, which appears between the 5th and 6th day after fertilisation) have the same rate of implantation, of evolutionary pregnancy and of a healthy born child.

The study, presented at the 35th Congress of the European Society of Human Reproduction and Embryology (ESHRE), which took place from 23rd to 26th of June in Vienna, was made possible by Embryoscope, an embryo incubator that incorporates a video camera that records their development. In IVF fertilisation treatments, embryos are classified according to guidelines based on their appearance and how they develop. In this way, those that are considered with a better prognosis are transferred to the patient for implantation and further evolution.

A sample of 23.340

With the standards currently in place, embryos that do not follow marked patterns are considered to be less likely to develop. In this sense, Institut Marquès is reassessing these guidelines. Thus, it has shown that many standard criteria are wrong.

The retrospective study analysed the development of 23.340 embryos, from fertilisation to blastocyst stage. In 303 of them the presence of complete absorption of one of their cells is observed. These showed a slight decrease in the proportion reaching blastocyst stage, but the birth rate is maintained. This fact suggests that this absorption would involve the early detection of errors by cells. The embryos that are able to overcome this repair present the same reproductive potential.