I see there is concern from some of you, and you are hesitant to call a
pumping mother's large supply an oversupply. From the mothers I've worked
with, it is not common, but it is easy to encourage in a few mothers, and I
found problems later on down the road  when we encouraged such oversupplies(we
don't have a close milk bank. We use it when we can, and those mothers donate
their milk).  The types of problems seen, ware similar to other oversupply
problems, and the babies have difficulties controlling the flow, gulped a lot,
mastitis, etc.
The one month to six week drop in supply was much more common, but it needs to
be anticipated and mother needs to take measures to increase it when it is
seen. This is why NICU's need LC's and enough  well educated staff  to
identify problems as they occur.
The main thread that I have seen is possible for most mothers to pump and
maintain a milk supply, and small babies and mothers can go home breastfeeding
with little  (if any )pumping, and they can breastfeed for extended periods.
They need support, encouragement, time with each other to learn, and educated
guidance.
Fritzi Drosten RN, IBCLC
Piedmont, CA