Stopping the biological clock - Freezing eggs using vitrification at Malpani Infertility Clinic
Posted Dec 07 2008 12:00pm
IVF labs have been routinely freezing sperm and embryos for many years. However, freezing eggs has always been a challenge. This is because the egg is the largest cell in the body and contains a large quantity of water. Using conventional slow freezing techniques meant that this intracellular water would often form ice crystals while the egg was frozen, resulting in the egg being damaged.
However, using a new technique called vitrification ( vitros = glass) or flash freezing, we can now reliably freeze eggs as well.
How does vitrification work ? The principle is simple. This new method of cryopreservation allows ultra-rapid freezing. We put the eggs in very small droplets of vitrification solution in special straws, and plunge them directly in liquid nitrogen. This means the egg is cooled from 37 C to -196 C in a few seconds , so that the water does not get a chance to crystallize ! Vitrification uses a very high concentration of antifreeze solution (DMSO and ethylene glycol), allowing instant super-cooling into solid with no ice crystal formation at all.
Of course, it is not quite as simple as it might sound. Such high concentrations of antifreeze could be toxic to cells. This is why technical skill, experience and expertise is critically important !
Using this vitrification technique for freezing, we can reliably preserve eggs as well as embryos so that the pregnancy rate is as good as with fresh eggs.
This breakthrough will now allow us to offer the following additional services to our patients
- Formation of donor egg banksto facilitate and lessen the cost of oocyte donation. We can ship these frozen oocyte anywhere in the world. However, it is critically important that the receiving IVF lab have enough expertise in vitrification, to be able to thaw these properly
- Provision of egg cryostorage for women who wish to pursue their career and want to postpone childbearing.
Just like the introduction of birth control helped to revolutionise the way women led their lives by giving them control over when to have children and how many children to have, egg vitrification can allow the new generation of women to pursue their career without compromising their fertility, so that they can have their cake and eat it too ! This can be very empowering !