Why does embryo fragmentation appear?

What is fragmentation?

This is the separation of fragments of embryonic cells that do not contain a nucleus, that is, no genetic information. Such fragments can be formed during cell division inside the embryo on the second or third day of its development.

How to assess embryo fragmentation?

The degree of fragmentation is the percentage of non-nuclear regions of the cytoplasm to normal blastomeres (embryonic cells).

This indicator is so important that it is displayed in the classification of the embryo quality category.

A – the embryo has no fragmentation, all cells are symmetrical
B – the embryo contains up to 25% fragmentation, most of the cells are symmetrical
C – the embryo has pronounced fragmentation (> 25%), asymmetric blastomeres
D – the fragmentation of the embryo is more than 50%, the blastomeres are asymmetric.
Fragmentation of the embryo up to 25% is possible as a variant of the norm, which in turn does not affect its development in the future and subsequent implantation.

Severe fragmentation (> 25%) usually correlates with reduced production of excellent and good quality blastocysts.

Possible reasons for fragmentation:

Fragmentation serves as a programmed death for some embryos. In such cases, the cause can be attributed to genetic reasons. In our clinic, we recommend carrying out a genetic test for 37 genes that can potentially affect the arrest of embryo development.
Non-genetic reasons include: disturbances in the conditions of embryo cultivation, chronic diseases in a couple and negative factors (bad habits, exposure to toxins – smoking, evaporation of varnishes, resins, paints, radiation, chemotherapy), as well as inappropriate hormonal stimulation.
Unfortunately, the higher the degree of fragmentation of the embryo, the worse the prognosis for further development. It should be noted that there are cases in which embryos with a severe degree of fragmentation formed blastocysts of good quality on the fifth or sixth day.

Thus, fragmentation of the embryo on the second and third days of development should not frighten the couple; in such a situation it is possible to obtain embryos, however, preimplantation genetic testing (PGT) is recommended.

In our clinic, a consultation of a couple by an embryologist on all issues of embryo development, their peculiarities with a photo report of each day of cultivation is part of the IVF program. We discuss such important issues in simple language. This gives the couple an understanding of the situation at such an important stage in their journey to parenting!