A low-tech simplified form of IVF that uses baking soda has the potential to slash the cost of assisted conception.

The process could bring IVF within reach of millions more childless couples around the world, research has shown.

The technique, which does away with expensive labs, clean rooms and incubators, could cut the basic cost of IVF by up to 90%, experts predict.

Combined with other measures it opens up the prospect of IVF for less than £200 per treatment cycle - a fraction of the £5,000 average at modern clinics in the UK.

Yet the system is just as good as conventional methods at producing viable embryos, according to a "proof-of-concept" study.

In fact, some of the best quality embryos selected by experts in the head-to-head comparison test conducted in Belgium were created by the "baking soda" technique.

Although the new method is aimed at the developing world, it could also spark a revolution in the West, where access to IVF is restricted by the high costs involved.

Fertility expert Dr Allan Pacey, senior lecturer in andrology at the University of Sheffield and chairman of the British Fertility Society, said: "We need to exercise caution because this was an experiment in a lab in Belgium replicating what might happen in Africa.

"But I think if it ever was shown to work in Africa or elsewhere in the developing world it would be foolish for the West not to look at it.

"The system we use today is the result of a series of historical accidents and step changes. It takes something like this - someone thinking 'outside the box' - to revolutionise the way we do things.

"If this works as well as they're predicting, it's exactly the sort of thing the NHS would like to look at and embrace. It's a no-brainer."

The technique is known as WE after the Walking Egg foundation, a charitable organisation promoting global access to fertility treatment, which supported its development.

It is based on a pared down incubating system consisting of two connected glass tubes.

One tube generates carbon dioxide (CO2) by combining citric acid and sodium bicarbonate, or baking soda.

The CO2 keeps acidity levels stable in the second tube, which contains a culture medium and where fertilisation and embryo development takes place.

Eggs and sperm are injected into the second tube without disturbing the air environment inside.

Fertilisation and embryo growth can simply be observed through the glass walls of the tube.

In the proof-of-concept study, WE outcomes were compared with those from a conventional IVF system, using eggs from a group of women under the age of 36.

Interim results presented in London today at the annual meeting of the European Society of Human Reproduction and Embryology (Eshre) showed similar rates of fertilisation from both systems.

However in 23 out of 35 treatment cycles (65.7%) the top quality embryo chosen by an independent embryologist originated from WE.

The low-cost system achieved a pregnancy rate of 30.4%, which matches the IVF average, and by the end of May this year had led to the birth of 12 healthy babies.

The first low-cost baby was a 3.5 kilogram (seven pound) boy born after 40 weeks' gestation.

One WE miscarriage was recorded after an eight-week pregnancy.

Lead investigator Dr Elke Klerkx, from the Genk Institute for Fertility Technology in Belgium, said: "Our initial results are proof of principle that a simplified culture system designed for developing countries can offer affordable and successful opportunities for infertility treatment where IVF is the only solution.

She said: "This is a major step towards universal fertility care."

Dr Klerkx added: "If combined with single embryo transfer and low stimulation protocols, we estimate the cost of a treatment cycle can be less than €200, with laboratory costs between 10% and 15% of those in Western-style programmes."

At present, effective assisted conception remains the preserve of developed countries.

"Infertility care is probably the most neglected healthcare problem of developing countries, affecting more than two million couples," said Dr Klerkx.

"The simplified lab procedure will undoubtedly open up a new era in the history of IVF.

The method not only offers affordable and successful access to IVF, but will make effective treatment techniques available to a much larger part of the world's infertile population.

"This, therefore, may also be considered an important breakthrough in terms of human rights, equity and social justice."

Describing the differences between conventional IVF and the WE method, Dr Pacey said: "In the West we use clean rooms and we all get dressed in special garbs with two changes of clothing to ensure nothing comes in from the environment." 

He continued: "We use big temperature-controlled incubators and air purification systems."

"This system strips all that away and you're left with a relatively small device that sits in the corner of a lab - it could be a general lab - and environmental control is really small scale."

He stressed that other factors besides the culture system used to fertilise eggs and incubate embryos, such as infrastructure, buildings, regulations and staff salaries, all contributed to the high cost of IVF in the West.

But even when this was taken out of the equation the cost saving from WE was very large.

One factor that had to be taken into account was the high standards of safety and hygiene IVF clinics in the UK had to meet.

"In the NHS you're not going to accept something that lowers your infection control levels, for example," said Dr Pacey.

Fellow British fertility expert Stuart Lavery, consultant gynaecologist and director of IVF at Hammersmith Hospital in London, said: "I think the potential for this could really be quite amazing."