Human breast milk is the best food for human babies. Although the evidence for some of the benefits is not as sound as I would like, I think it is clear that the benefits for preterm infants are substantial. Hence the growth in human milk banks, which are now supposed to be run according to standards which are similar to those for blood product banking (which makes the milk much more expensive than in the olden days). One possible risk of having such banks is that it might reduce the use of mothers own milk.
Two recent publications are reassuring; (Delfosse NM, Ward L, Lagomarcino AJ, Auer C, Smith C, Meinzen-Derr J, Valentine C, Schibler KR, Morrow AL: Donor human milk largely replaces formula-feeding of preterm infants in two urban hospitals. J Perinatol 2012.) 2 Hospitals in Cincinnati introduced a program to supply donor milk in 206, and progressively over the subsequent years, as donor milk increased, there was much less formula used, but no apparent effect on breast milk use.
The other is an observational study from a number of Italian NICUs, some of them had Human milk banks, and others did not; (Arslanoglu S, Moro GE, Bellu R, Turoli D, De Nisi G, Tonetto P, Bertino E: Presence of human milk bank is associated with elevated rate of exclusive breastfeeding in vlbw infants. J Perinat Med 2012:1-3). . Exclusive breastfeeding rate at discharge of very low birth weight infants was significantly higher in NICUs with a milk bank than in NICUs without (29.6% vs. 16.0%, respectively). Any breastfeeding at discharge was 60.4% vs. 52.8%, P=0.09. These are not very impressive rates, but they at least don’t suggest an adverse influence of having a breast milk bank.
Neonatal Research 
Keith,
Being the “breast milk neonatologist” in your unit (and having pumped for 14 months for Violette), I think these conclusions need to be made cautiously.
The context of the breast milk bank and how medical services are paid for in this equation are important. There are many factors that influence mothers’ motivation to breast feed (or pump) for their sick neonate. We know lactation consultants and other kinds of support by providers help mothers produce breast milk in enough quantities. Who pays for these services is key and how much breast milk costs is also important.
In some health care systems, breast milk is “free” for hospitals (the same as blood) BUT lactation consultants and providers supporting breast milk use are expensive. In these healthcare systems (like our Canadian HCS) where every penny is counted, it would be more difficult to request more support for lactating mothers if the golden-breast milk was actually free. And it may become so in Quebec in 2013.
This is NOT to say that breast milk banks are harmful, but the solution in this situation is that governments could demand that adequate support of mothers for the utilization of mothers own milk (MOM) be demonstrated before they allow a hospital to receive BM free-of-charge from banks, Or that breast milk actually costs something (which I suspect it does in the US) to hospitals. If we had to purchase expensive donor breast milk and formula costed as much, it would be a lot easier to have increased support for breast feeding mothers. I am convinced that for babies (and mothers?) unpasteurized MOM is better than banked milk, but this is a personal opinion with no strong data (I know, you never have any of these…)
Annie