Edie:
I get calls from mothers asking where to purchase nipple shields and I tell
them that the reason that they are hard to find in our area is because they
are a bandaid solution and don't address the real problem which is usually
positioning.  Nipple shield use has also been found to reduce breast
stimulation (especially important while in the process of establishing an
adequate milk supply) which negatively impacts milk production and therefore
reduces the amount of milk received by the baby.  Another major concern is
nipple confusion.  If a mother has flat or inverted nipples it is even more
important to avoid artificial nipples as baby can get 'hooked' very quickly.
 I have seen breast refusal result from nipple shield use.

Leona Simoes, LLLL