From Jack Newman, lactation expert in Canada

1. Not all premature babies are the same.  It may be that a baby born
at 26 weeks gestation may require fortification of mother's milk, but
it does not follow that a baby born at 32 weeks needs it.  A premature
baby who is well can often do well on breastmilk alone, because large
quantities can be given (250 cc/kg/day or more).  If the baby is on a
ventilator, for example, these sorts of volumes become difficult for
fear of inducing congestive heart failure.  I have this experience
from Africa, and we *never* used any fortifiers, except in the very
smallest we gave calcium and vitamin D, though I no longer remember
what criterea we used for this.

2. It has not been proven that babies need to grow at intrauterine
rates.  Taking this premise as a "proven" is one of the reasons that
fortifiers are felt to be "necessary", since it is probably impossible
even with the large volumes above to manage this with breastmilk
alone.

3. Even if we manage to achieve intrauterine growth rates with
fortifiers, there is evidence that the extra weight is fat and not
other tissue.  Is this what we want?  In fact, there is no evidence
that these babies are better off in the long run.  A recent study from
Scandinavia showed that the more breastmilk a baby got (compared to
fortifier), the *better* his bone density at two years.  The other
main reason for giving fortifiers is for the calcium.

4. Modification of breastmilk also can result in faster growth rates.
For example, using hind milk has resulted in faster growth.
Ultrasound homogenization results in less fat sticking to tubes.
There is no reason why banked milk cannot be used as fortifier, and
the technology is obviously there to make protein, fat, other
supplements using milk from donors.  In Vancouver, the milk bank
provides "premature" donor milk for premature babies.