Melbourne IVF is working on several areas of advanced science.
Metabolomics
Since the early days of IVF, embryologists have sought to find ways of identifying the embryos in the laboratory that are the most likely to result in pregnancy. The ability to select the “best” embryo is of crucial importance since the risks associated with transferring multiple embryos are well recognised and most IVF centres now aim to transfer a single embryo whenever possible.
Assessment of the developing embryo under a light microscope can give many clues to the “quality” of the embryos. We know, for example, that embryos which develop at a specific rate and pass through crucial developmental stages at the appropriate time will have a higher chance of giving rise to a pregnancy. Although careful observation of embryos at the correct times of development can identify these features as well as particular abnormalities which reduce the chance of pregnancy, it is very difficult to gain more detailed functional information about the embryo.
Recently, studies carried out at Melbourne IVF have explored the possibility that very sophisticated analysis of the chemical composition of the culture medium in which the embryo develops may give information relating to the metabolic activity of the embryo. The aim is to identify the metabolic characteristics which may be associated with the most viable embryos.
Tiny volumes of culture medium are analysed by a technique known as “Near Infra Red Spectroscopy” and the changes which have been caused by the embryo’s metabolic activity (referred to as the “Metabolomic Profile”) are analysed. We then look to see if there are changes which are more often caused by embryos which go on to form pregnancies.
This work is still in the experimental phase but early results are promising and our work has already been recognised by a scientific award which allowed the research to be presented at a major international conference. It is hoped that this technique may be available to patients in the near future.
Cryopreservation of Reproductive Potential
Melbourne IVF has a long history of research and development in the area of cryopreservation (freezing) and our scientific staff have published many important research papers and book chapters on the subject of low temperature storage of embryos, oocytes (eggs), and ovarian tissue.
Embryo cryopreservation
Although embryo freezing has been available for over 20 years, the technology had remained static for most of this time. As the trend towards transferring only a single fresh embryo has increased, the importance of embryo cryopreservation has also increased. The need to ensure that as many embryos as possible survive the freezing and thawing procedure led us to search for potential improvements in the technology. In the last 5 years, research carried out at Melbourne IVF has led to significant improvements in the outcome from embryo freezing.
Embryos which have undergone biopsy (cell removal) for preimplantation genetic diagnosis (PGD) had, for some time, been known to be extremely sensitive to cryopreservation. Since Melbourne IVF has a very active PGD programme, we were extremely keen to overcome this obstacle. By modifying the way in which these embryos were dehydrated before freezing and the way in which they were rehydrated after thawing, we were able to significantly improve the outcome for frozen PGD embryos. Dehydration is a crucial aspect of cryopreservation since the conversion of water to ice inside the embryo can result in irreversible damage.
The principles applied to cryopreservation of PGD embryos have now been applied in the development of a new method for freezing all our embryos. This research work has been published very recently in one of the top journals in reproductive medicine. We have demonstrated clearly that over 90% of all embryos will survive cryopreservation using this new method. This gives us even greater confidence in pursuing the goal of single embryo transfer in most cases.
Oocyte (egg) cryopreservation
While embryo freezing has been available since the early days of IVF, it has proved to be much more difficult to freeze human eggs. This is because the mature human egg is in a biological state which is extremely sensitive to low temperatures. Being able to freeze eggs rather than embryos is particularly important for women without partners who may be about to lose their fertility for a variety of reasons. Researchers at Melbourne IVF have been recognised worldwide as pioneers in this field.
In recent years, a number of pregnancies have resulted from the use of frozen/thawed eggs in our clinic and we are continuing to explore improvements in the methods used. This research has involved manipulating the water content inside the eggs and the results obtained have also formed the basis for our improved methods for freezing embryos which are mentioned in the preceding section. We are also currently assessing new methods of ultrarapid freezing using a technique called vitrification which avoids the formation of ice.
Ovarian tissue cryopreservation
For many young women with cancer, chemotherapy and/or radiotherapy may cure their disease but leave them unable to conceive. This is because the treatment also results in the destruction of their eggs which exist in tiny structures in the ovary called primordial follicles. Researchers at Melbourne IVF have also played a crucial role in the development of techniques for cryopreservation of slices of ovarian cortex, the outer coating of the ovary which contains these follicles.
Award winning research from our group has demonstrated that these follicles can survive freezing and thawing and also go on to resume normal development. This has been shown for small pieces of tissue frozen from many different patients. More recently, we have been the first group in Australia to transplant this frozen/thawed ovarian tissue back to patients and have shown that the tissue is capable of functioning after the transplant.