In-vitro maturation

IVM – In vitro maturation - is a procedure recommended for women who do not respond well to IVF treatment (not enough eggs are produced, no eggs are mature or when there is a high risk of OHSS - ovarian hyper-stimulation syndrome.

The overall success rate of IVM is lower than for IVF. However it may be the only solution for some patients. Scientists around the world are carefully studying the possible causes of this lower success rate; but as always in this field, it is never a simple story.

During the treatment with in-vitro maturation (IVM), eggs are collected from the ovaries when they are still immature. They are then matured for a couple of days in a dish in the laboratory before being fertilised (immature eggs cannot be fertilised.)

This means that the amount of hormonal stimulation required is greatly reduced before the eggs are collected. This is particularly beneficial for women who cannot receive this hormonal stimulation (due to a high risk of OHSS - ovarian hyper-stimulation syndrome) or for the ones who do not respond well to the treatment. Once fertilisation^? has occurred, the process continues in a very similar style found in IVF or ICSI.

During the IVM protocol, the nucleus and cytoplasm of the egg need to mature. However, it appears that it is not sufficient: the granulosa cells, the small cells surrounding the egg, also need to mature.

Dr Hamamah’s team has identified that several genes were expressed differently in these cells in vivo (in the body), compared to in vitro (in the laboratory). These studies of gene expression may be the first step in gaining a better understanding of the biological process behind the lower success rate of IVM.

Looking at the chromosomal content of the eggs, Dr Reqena has identified that only 56% of eggs were chromosomally normal from an IVM protocol, compared to 86% for IVF. This can reflect how careful the body is at selecting the best egg to “use” every cycle. In a natural cycle, the chromosomal content of the egg is probably higher than in an IVF cycle.

The safety data from IVM is already available, in particular from McGill University in Montreal - Canada where they have been doing IVM for many years. So far the safety data for the child is good with no further risks than the existing risks identified from IVF.

Scientists then discussed the benefits for the woman and all agreed the IVM was less traumatic for women and may be a good alternative. Some even reported that this technique could work better than IVF for women with low ovarian reserve (when their ovaries do not respond well to the treatment).

Dr Child discussed the possible use of IVM for fertility preservation for oncology patients. The audience was divided. On one hand IVM is less traumatic for a woman about to undergo a very traumatic procedure (cancer treatment). However the success rate is lower and she only has time to have “one go” at preserving her fertility.

There is still a lot of work before experts decide if IVM could replace IVF. At this stage the patient needs to know that even though the medical treatment is less intensive for the woman, the success rate remains lower.

For more information on Fertility preservation read here about Cryopreservation.

Ovarian reserve can be tested by measuring AMH levels. This is a useful blood test to establish how well a woman may respond to IVF treatment. It can also indicate cases where IVM may be a potentially better option than following IVF treatment. DuoFertility offers AMH testing to those currently based in the UK. Read more about AMH testing.