Repeated poor embryo development
What is repeated poor embryo development?
The quality of an embryo is determined under a microscope. We look at:
- cell number and developmental stage,
- the fragmentation (fragments of cells between the cells),
- size symmetry of the cells,
- the granulation in the cell,
- vacuoles in the cells (a specific part of the cell),
- and multi-nucleation in the cells (there should only be one nucleus per cell).
The quality of the embryo is expressed in an ABCD system:
- A means excellent quality,
- B is good quality,
- C is fair quality and
- D is bad quality.
In the future an additional scoring tool to determine the quality may be added: an imaging technique which photographs the development of the embryo at regular times (time-lapse) for a more accurate monitoring of the development.
Repeated poor embryo development means you had several IVF/ICSI treatment cycles which produced low-quality embryos. This implies you either had no embryos available for transfer or freezing because they were bad quality or only embryos of fair quality. Poor embryo quality decreases the chances of pregnancy.
Am I a poor developer?
It is not because you had a bad or fair quality embryo that you immediately fall in this category of patients. However, if, in repeated treatment cycles your embryos were of poor quality, you are a “poor developer.
It is difficult to predict whether your embryos, following IVF or ICSI, will be poor quality. However, there are conditions with an increased risk of poor embryo quality:
- poor oocyte quality,
- extremely poor sperm quality,
- poor embryo quality in a previous IVF or ICSI cycle.
However, often the real cause cannot be determined as functional aspects of sperm and oocytes cannot always be assessed.
- Oocyte factors
The first steps of embryo development (up to the 4- to 8-cell stage) are controlled mainly by the oocyte:
- oocyte quality problems. Oocytes may be severely granulated, contain many vacuoles or other visible abnormalities which may lead to poor embryo development;
- Oocyte maturation problems. Oocytes may have nuclear maturity but not fully cytoplasmic maturity, which cannot be assessed under the microscope, but may result in poor embryo quality.
- Sperm factors
Although sperm effect mostly impacts ‘late’ embryonic development (after the 8-cell stage), ‘early’ embryo development can also be affected. The following are possible:
- sperm morphology problems.
when only sperm with a very abnormal form can be selected for injection, the risk of poor embryo development increases;
- sperm DNA abnormalities.
Sperm DNA damage may have an impact on the early stages of embryo development although the effects are more apparent during the later embryo stages (8-cell stage up to blastocyst stage).
There is not so much we can do.
- You could make some changes in your lifestyle. For instance, if you smoke, you should stop. We know that nicotine has a bad effect on eggs and egg quality.
- We can propose an alternative follicular stimulation protocol with closer monitoring for a better oocyte quality in a possible next treatment cycle.
- If different stimulation protocols fail to improve embryo quality, a managed natural cycle may be suggested, without (much) stimulation.
However, the cause of poor embryo development may be difficult to find, and poor embryo quality may be inherent to the intrinsic quality of the oocytes and sperm.
Poor embryo development due to sperm factors may be solved by the technique that is also used to treat sperm failure to activate the oocyte (see repeated bad fertilisation).
This can be done in a so-called “split cycle”. Half of the oocytes are fertilised using the conventional ICSI technique and the other half of the oocytes are fertilised using ICSI in combination with artificial oocyte activation.
If oocyte activation does not result in a better embryo quality, another split cycle can be performed. In this case half of the oocytes are fertilised with your partner’s sperm and the other half with donor sperm.
This diagnostic strategy may help to identify the underlying cause of the problem.
If treatment with donor material is worth considering, there are two possibilities:
- if poor embryo quality is observed with both split cycles, oocyte donation may be an option.
- if embryo quality improves by using donor sperm, sperm donation could be considered.
Obviously the decision to switch to treatment with donor material is entirely up to you.