Research identifies problems for lab-matured eggs

Researchers from Yale University have been looking at egg development in the laboratory, and may have found some clues as to why in-vitro maturationn (IVM), hailed of late as a great new advance in assisted reproduction, doesn't have higher success rates.

In standard IVF, eggs grow in their natural environment in the ovary and are given their last hormonal boost to mature them inside the female body. However, IVM, or in-vitro maturation, involves taking immature eggs from the ovaries and maturing them in the laboratory. It uses less drugs and is cheaper than IVF, so was heralded by many as a significant way ahead, but it is not suitable for everyone as you need to have lots of immature eggs in the ovaries to make it worthwhile.

The research team looked at eggs matured in the laboratory and compared them with eggs that were matured in the woman's body, and found that there were significant differences in their genetic development. The eggs matured in the lab had differences in their gene activity as they developed, and in their genetic profile.

This new research suggests that we don't yet have the ideal laboratory conditions for maturing eggs, and this may be why IVM success rates are not higher. The research team were aiming to find better ways to culture these immature eggs, and to identify the eggs most likely to lead to a pregnancy. The details of the research are on the Yale website " www.yale.edu

IVM - is it for you ?

Anyone with an interest in fertility is likely to have heard the recent news about the first babies born in the UK after a new type of treatment called in vitro maturation, or IVM. The glowing newspaper reports on the subject suggested IVM was about to revolutionise fertility treatment. Cheaper than IVF, less invasive and less risky, it sounded the perfect solution and patients could be forgiven for rushing off to their clinics to demand it immediately. The reality is that IVM is not yet widely available, and is not suitable for everyone anyway.

IVM doesn't use drugs to get women to produce lots of eggs. Instead, it involves taking immature eggs straight from the ovaries, maturing them in the laboratory, and then injecting them with sperm. The technique relies on women having lots of immature eggs, and success rates are low for anyone with normal ovaries who is unlikely to have sufficient quantities to make it worthwhile. IVM is most suitable for younger women with polycystic ovaries because they tend to have an abundance of immature eggs, but even then, success rates are not particularly high at between 20 and 30%.

IVM is a relatively new technique, which has only produced 400 babies worldwide so far, and at the moment only one clinic in the UK is licensed to carry it out. It is cheaper than IVF because you're not using any drugs to stimulate the ovaries, so you save on the hefty drugs bill. It also cuts out the risk of hyperstimulation, which is a particular danger for women who have polycystic ovaries when they take the stimulating drugs.

IVM is undoubtedly an exciting step forward in reproductive medicine, but the revolution the news reports may have led us to expect is still some time away.