For the premature baby, breast milk — with its immunoglobulins containing antibodies and other constituents — offers valuable protection against illness and infection.

It is also an excellent source of nutrition. “Breast milk promotes the growth of babies’ nerves, brains and gut with special factors that are not present in any other milk,” says Rosie Dodds, policy research officer at the National Childbirth Trust.

When a mother cannot provide sufficient amounts of her own milk — usually because the premature birth means that she hasn’t started lactating properly — another option for premature babies is so-called donor breast milk.

This milk is a rare and precious gift provided by altruistic women willing to donate their excess. Hitherto, the collection and processing of donor milk has been a non-profit business, but recently a US company launched itself as the world’s first centralised facility for buying and selling human breast milk. The Californian firm, Prolacta Bioscience, has begun supplying American hospitals with the equipment for collecting and screening the milk, which will be bought, processed (pasteurised), and then sold back to the hospitals. The donor women will not be paid.

The non-profit Human Milk Banking Association of North America (HMBANA) has 12 banks which operate individually. In Britain there are 17 banks — as in America, there is no central processing unit and so the milk is processed at each hospital.

The present system cannot nearly provide for all the needy babies in America, says Elena Medo, Prolacta’s chief executive officer. She says that donor milk supplies are so low in the US that only 1 per cent of the 55,000 babies born under 1,000g (2lb 3oz) in weight have access to donor milk, and this is before low birth-weight babies even come into the equation.

The commercialisation of donor breast milk has its sceptics. Frances Jones, the chair of HMBANA, argues that the American HMBANA banks “have freezers full of milk and would be pleased to supply any child referred to them with a physician’s order. The problem seems to be a lack of awareness of the resource and willingness to order donor milk rather than a shortage of donor milk.”

Furthermore, according to the HMBANA, “introducing the profit motive could put the infant of the lactating mother at risk if she feels pressure to provide a certain volume of milk to a bank or a recipient rather than feeding her own infant”.

Gillian Weaver, the chair of the United Kingdom Association for Milk Banking, while welcoming any advances that can be shown to reduce risk and in addition help more premature babies receive donor milk, has reservations about any initiatives “that fall outside the control of established healthcare settings, particularly if they are encumbered with the need to make a profit”.

And how would the mothers themselves feel? Julie Grove White, a British mother who has donated breast milk in the past, says she would have been reluctant to do so if there were a profit-making element. “I would question the motivations of those participating in the scheme if money is involved as I consider breast-milk donation a gift,” she says.

However, the idea of altruistic donations forming part of a commercial business is not a new one. In the US, for instance, a similar system for blood banking has long been in place.

Furthermore, Medo says that her company would actually encourage more women to donate — she believes that many don’t do so now because they cannot afford the pump. (Medo has previously manufactured breast pumps and worked with large hospitals for more than 20 years.) Prolacta provides a free electric one that would otherwise cost $390 (£220), and which the woman can keep regardless of how much milk she donates.

Moreover, “owning the pump means mothers can breastfeed their own child for longer because they will be able to express when they return to work,” she says.

Some of the American hospitals will lend electric pumps, while in Britain women can be lent hand pumps if needed.

Another benefit, says Medo, is that “when women donate they will be helping to improve the lactation facilities at that hospital, since we supply the hospital free with everything they need to collect the milk”.

This means that a hospital which participates in the Prolacta scheme will be given all the equipment that is needed to collect and store the milk from the donors where this may not have been possible before. The hospital also has priority on buying milk products back from Prolacta.

Medo accepts that ethical issues are involved. “We are very conscious of those. But our view is that there should be a milk bank in every place where there are sick babies, and under the current model this hasn’t happened.”