This week marks 25 years since a few litres of liquid nitrogen changed the birthing world and made medical history.

Turn the clock back a quarter of a century and medical history was written using industrial gas, as the first baby from a liquid nitrogen-frozen embryo came into the world.

During thate brave new world of 1984,with its iconic George Orwell fame and right on cue for raised-eyebrow conspiracy theorists, the moment of marvel took place. On 28th March, baby Zoe was born in Melbourne, Australia, weighing in at a healthy 5 lbs approx.

Now 25 years later and in a modern society where around three million babies have been born through assisted reproduction techniques, it seems fitting to look back on a day when a few litres of liquid nitrogen changed the world.

Public opinion has changed greatly since then and IVF techniques are commonly accepted around the world, with around 20% of the three million babies born via assisted reproduction derived from frozen embryos. So why was this technique so revolutionary? And how has technology changed since then?

Pioneering with gases
Dr Alan Trounson and Dr Carl Wood made medical history on that day in March 1984, having taken the pioneering decision to try ‘test tube’ fertilisation and embryo freezing with Zoe’s parents – her mother was a 33 year-old New Zealander and her father a 38 year-old British-born Australian resident.

The concept of a test tube baby wasn’t new and Louise Brown had in fact become the world’s first ‘fresh test tube baby’ in England some six years before. Experimenting with a frozen embryo was a radical new concept however, and so this momentous chapter in history began.

Zoe’s mother produced 11 eggs, which were then frozen using a special controlled rate freezer manufactured by London company Planer plc, before being stored in liquid nitrogen. Having been frozen in liquid nitrogen, the embryo was later thawed and implanted – a freezing procedure which is now commonplace in the modern world.

The deep cold of liquid nitrogen is needed to stop any biological action and using mechanical type refrigerators, even very cold ones, is not feasible. Many of the cells needed for medicine are difficult to freeze and are frozen down at a predefined protocol, preventing damage to cells before they are then transferred to liquid nitrogen storage tanks.

Cryogenic storage at very low temperatures is presumed to provide an indefinite, if not near infinite, longevity to cells although the actual ‘shelf life’ is rather difficult to prove. In terms of the cell or ‘product’ quality meanwhile, at the time of Zoe’s birth there were some anxieties over the safety of the new technique.

However 25 years later, separate studies published in 2008 from Denmark, Australia, the US and Finland examined quite a large number of frozen births over the previous 10 years and indicated that, if anything, frozen embryos developed into healthier babies than the 'fresh' IVF embryos.

Geoffrey Planer, Chair of Planer plc, spoke of the merits of this liquid gas powered method and told gasworld, “Our team in Sunbury has been helping scientists with their discoveries for thirty years – but it’s a first for us to be able to wish one of those discoveries a happy twenty fifth birthday!”

Then and now…
A lot has changed and developed in the past 25 years, in both technology and public perceptions of such a hot topic. Freezing processes have evolved both since, and as a result of that historic first and further advances are likely for the next 25 years.

The controlled rate freezing technique used for Zoe helped the development of controlled rate freezers, like Planer’s, that are now such an adjunct to the dewars and liquid nitrogen refrigerators made by companies like Chart, Taylor Wharton and Air Liquide.

Most IVF laboratories now have controlled rate freezers and liquid nitrogen facilities, while the freezing techniques learned in the IVF process were refined in conjunction with those needed for storing other cell lines - such as bone marrow for transplants in leukaemia treatment and more recently stem cell storage.

The preservation of biological matter is increasingly important, because human and animal tissue needs to be stored for research and regenerative medicine purposes: bone marrow for cancer treatment; blood products for collection of stem cells and transfusion; sperm, eggs, embryos for fertility; skin, bone and cell lines for transplantation; plant cells, algae cultures, protozoa, seeds and fungi for the purposes of sustainable agriculture, biotechnology and conservation and biodiversity.

Scientific researchers’ attention is also now turning towards the preservation of other, often larger, samples which are currently impossible to successfully freeze and thaw - such as cartilage.

If research and testing is successful, perhaps one day even whole organs might be preserved using freezing gases, for later transplantation.

And what of those pioneering figures of 1984?
Dr Alan Trounson is now President of the California Institute for Regenerative Medicine in San Francisco and before that, held the position of Professor of Stem Cell Sciences and Director of the Monash Immunology and Stem Cell Laboratories at Monash University, Australia.

Louise Brown, the first IVF baby, recently had her own child - naturally conceived – and what of Zoe? All these years later, she has finished her degree in Australia and has now started a career in law. Happy Birthday Zoe!

Finally, what of Planer? The company has continued to advance in the field of measurement and control of physical parameters related to cell safety in hospitals, laboratories and universities. Having pioneered the development and use of products for controlled rate freezing, the company received the Queen's Award for Technology and awards from the British DTI for Innovation and Good Practice in Micro-electronics.

Customers who depend on the viability of their stored samples use Planer products, which include programmable freezers, incubators, monitoring equipment and software for the viable storage and preservation of medical and biological specimens.