And the medical facts are supported by equally persuasive economic research. Studies in the United States have shown that failure to breastfeed leads to increased health-care costs: for instance, infant diarrhoea that could have been prevented by breastfeeding costs nearly US$300 million (HK$2.32 billion) each year.

And in Australia it has been estimated that increasing the number of exclusively breastfed three-month-olds from three out of five to four out of five would save US$11.5 million a year in costs of hospitalisation and treatment for illnesses including gastro-intestinal problems and eczema.

Yet in Hong Kong most mothers are like Ms Leung. Fewer than half of new mothers breastfeed at all, and more than half of those stop after one month. The figure drops by another third after eight weeks.

That falls far short of the United Nations recommendation that babies be exclusively breastfed until they are between four and six months old. Part of the problem is within the Hospital Authority, which offers mothers infant formula against international guidelines.

Now a new group is trying to change that by bringing the issue into the open.

A stark advert in MTR stations stands out from its neighbours for its lack of a Canto-pop singer, a pretty girl or a sitcom star.

Instead it shows a larger-than-life black-and-white picture of a baby in its mother's womb. It could be a routine ultrasound picture of a developing child - its head oversized, its facial features not fully formed - until you notice that the tiny, translucent hands are clutching a baby bottle. At the side the Chinese text is strong: 'Beware of the Neo-Human; the Non-Mammal.' The message is clear and harsh - a baby that is not fed naturally is not a full human being.

The advert is the first in a series from the Hong Kong Breastfeeding Mothers' Association.

For the first time, the mass media have been used to elicit support for something regarded by most as a marginal activity more suited to new-age Westerners or country cousins on the mainland rather than Hong Kong's city-slickers. The group fears both long-term health problems for thousands of babies, and the loss of bonding between mother and child.

The baby still in the womb has no choice about what kind of milk it will receive once born, says association chairwoman Vivian Tai Yuet-kam.

'Even before the baby is born, the mother, and often the other family members and friends, have already decided that the baby will be bottle-fed. We want to remind people that bottle-feeding is not natural.' The campaign is about to move into a second stage. Riding on the back of the recent protests about pirated films and CDs, the next poster shows a human fist smashing a baby bottle, while the slogan exhorts consumers to 'strike out at fake products and support the original product'.

Association executive member Connie Chiu Siu-wai says she remembers as a child 30 years ago seeing mothers feeding babies on the street. She worries that the next generation is being denied that experience.

'It's just like the zoo animal; if you put them in the forest they'd die because they've lost the instinct to catch prey. It's the same thing. A mother should know instinctively how to breastfeed and the baby know how to suck, but we've destroyed that.' The campaign advertising is being provided free by the Hong Kong branch of the US-based advertising company, Bozell Worldwide. The idea of the first advert is to push the public slightly beyond where they feel comfortable, says associate creative director Antonius Chen.

'We think this poster will be right on the line [of what people find acceptable] and we want to exploit that. I think it's about knowing what people can accept and trying to push it. For this poster we chose to push it in quite a harsh way.' Breastfeeding rates in Hong Kong have improved dramatically during this decade. In 1992, only 19 per cent of women breastfed their babies on discharge from hospital - by 1998 that figure had leapt to 47 per cent.

But breastfeeding rates still compare badly with other countries.

In Scandinavia it is estimated that 99 per cent of mothers are breastfeeding when they leave hospital; in Canada the figure is 80 per cent, and perhaps most pertinently, on the mainland, the national average for breastfeeding on discharge from hospital is more than 90 per cent.

The Hospital Authority says it is policy to encourage all new mothers to breastfeed their babies, that information is given regularly at ante-natal classes and that nursing staff are trained to teach mothers breastfeeding techniques during their stay after having the baby. Education of mothers and families is most important, says authority senior executive manager Dr Liu Shao-haei.

Yet many new mothers say this is not their experience.

Cynthia Lo Siu-ying gave birth to a baby girl at Tsan Yuk Hospital in January.

She had planned to breastfeed and told the nurses to bring her baby to her from the nursery when it was hungry. Yet despite her instructions, the nurses gave her daughter formula from a bottle while in the nursery.

Having drunk from a bottle, the baby then found it hard to latch on to the breast. Although Ms Lo then used a pump to express milk for her daughter when she returned home, she was never able to breastfeed the baby.

'We'd been told in ante-natal classes that the hospital supported breastfeeding, but they don't have the manpower to carry it out,' says an angry Ms Lo.

'The nurses were too busy, and giving my daughter a bottle was an easy way out.

'I was very upset. I'd hoped to feed my baby myself until she was at least nine months old . . . I feel cheated by what happened.' In a similar but ultimately happier experience, Ruoyu Smith wanted to breastfeed her baby daughter when she was born at Adventist Hospital last month.

But in the first few days, when baby Chloe cried, the nurses suggested Ms Smith try formula.

'Some of the nurses said maybe she was crying because I didn't have enough milk. I didn't know any better so I agreed.' Only later did she find out from a paediatrician that it is normal not to have much milk in the first few days - in fact, the baby's suckling encourages lactation. Fortunately Ms Smith could continue to breastfeed.

'At the beginning it was hard work, but I know what I'm doing is the best for my baby and I can see the results. She's happy and healthy and that makes me feel good.' Yet despite these examples of nurses giving or suggesting its use, the authority insists that 'no milk supplements are given to breastfed babies unless medically indicated or after a very strong request from the mothers'.

The uphill battle is not helped by stiff competition from the producers of infant formula.

An international code drawn up by the WHO, which was adopted by the World Health Assembly in 1981, states that infant formulae may be sold, but they must never be promoted.

That means no advertising to the public, no free samples to mothers and no promotion within the health-care system.

But watch the television or visit a pharmacy and you will see adverts for formula.

Most importantly, free samples are available to mothers in hospitals, in direct contravention of the code.

A Consumer Council survey in August 1997 found that of 15 brands of formula suitable for newborns, none complied completely with the code.

Dr Constancia Wu, an executive member of the Baby Friendly Hospital Initiative, which promotes breastfeeding in hospitals, says aggressive marketing by the formula companies is a serious obstacle to the promotion of breastfeeding.

'Even on TV, which is probably the most powerful form of advertising, you see ads for milk formula and breastmilk substitute. This is an outright violation of the code.

'A few concerned individuals will write to the newspapers about this violation, but, because there's no legislation, the companies can do whatever they like,' she says.

Nestle Hong Kong, one market leader, claims it gives samples 'because the responsible health officials have requested that we do so'.

'In Hong Kong and in developed countries with similar policies, we do so only in response to written requests from the hospitals,' added a spokesman.

Dr Liu defends this practice for 'practical reasons' because 'hospitals need to provide some mothers with breastmilk substitute'.

Asked why the authority does not buy formula as it does any other food, he says: 'If the samples are available, that is beneficial to all parties, so why not use them?' Gabrielle Palmer, author of The Politics of Breastfeeding and a trainer of breastfeeding support to hospital staff on the mainland, retorts that accepting free samples is unethical because it encourages use and has been shown to reduce breastfeeding rates worldwide.

'The formula is not a gift, it's a marketing tactic. If a mother starts using one brand of formula in the hospital she will probably stick to it. It's very unethical for health professionals to be colluding with a marketing tactic in their health facility.

'They [formulae] should be treated like a prescription drug and their use carefully monitored, because giving a baby anything other than breastmilk is risky and should be managed very carefully.' So far about 20 countries, including the mainland, have incorporated the code into legislation.

Yeong Joo Kean, legal adviser in Penang for the Asia-Pacific office of the International Baby Food Action Network, which campaigns against marketing of infant formula, believes legislation can be effective. In India, for instance, several cases have been brought against formula companies since the code was made law in 1992.

'The impact of legislation is difficult to gauge and does not manifest itself immediately, but aggressive marketing on the other hand infiltrates into and lingers in the minds of its target audience for years, if not a lifetime.' Ms Yeong says Hong Kong should adopt legislation to bring it in line with the mainland.

'Hong Kong is the gateway to China and breastmilk substitutes will infiltrate the mainland market, thus defeating the headway which has been made in China in protecting breastfeeding.' Some feel that this is precisely what the formula companies plan. Ms Palmer says firms are targeting the huge potential market in Asia.

'The companies know they must change traditional breastfeeding cultures into 'modern practice' where the mother breastfeeds for a few weeks, then bottle-feeds for years. The birth rate in Asia will continue to be much higher than in the West for some time and they cannot just let all those potential customers breastfeed.' But Nestle Hong Kong says it is company policy to comply with the letter and spirit of the WHO code and it has not recently targeted Asia.

'Nestle has been selling infant formula in China since the beginning of the century and has been well established in other Asian countries for decades . . . there is no particular emphasis on Asia as a new market.' The Hospital Initiative's Dr Wu says the Hong Kong Government should look at the potential monetary savings from promoting breastfeeding.

'Many families would benefit financially by not spending their money on milk powders, and the Government would save money in health-care costs.

'But first and foremost we should consider the greater value of breastfeeding to human welfare. We should sustain, care and nurture life for our infants.

'This is our future generation, our children are our hope and our future.'