I also work as a in hospital LC and see outpatients. I have found as was
discussed that the amount expressed varies widely from patient to patient.
Frequently if pumping is initiated early enough, mothers may express more
on delivery day than they do on the day after. Those moms who have only a
few drops in the horns of the pump I tell them not to waste anything and
either use a clean finger (mothers) and just put this in the baby's mouth,
or we rinse some sterile water(not glucose water, unless sugars are low) to
push colostrum into the bottles and give this via small med cup to the baby.

The greates concern I have with pumping on the first few days is not
pumping long enough and not pumping correctly. It may seem that all people
should know that the pump goes well centered, over the areola, but often I
see circular marks and bruises on the breast  where the pump has been and
it isn't around the base of the nipple or on the areola. Sometimes it is
beside the nipple. Large breasted women may not be able to see the nipple.
Some women just don't seem to realize that the pump has sliped or has not
been applied correctly. Some do not realize that the pump is not applied
well enough to cause continuous suction. (sad but true)

 If I hear from staff that someone can get no milk after having pumped
several times, I try to find the time to see how they put the pump on, how
high they turn the suction up (in comfort Zone) and how long. I don't find
that for many women, especially those under stress let down within the ist
5 to 8 minutes. I usually suggest 15 minutes as a standard if it is
comfortable. We usually get something than.

Don't forget to teach gentle warmth and massage prior to pumping.(Sandra Lang)
A lot of encouragement is needed plus early pumping within the first day if
possible. Every little drop is an encouragement .

Attie Sandink RN IBCLC. Burlington Ont.