I think the question about the 4 hr test refers to the paper Tom Hale et al  published in which mothers pumped hourly for four hours or more.  (NOT waiting four hors to pump!)  He found that after 2-3 hrs, the volume pumped was consistent at about 1 oz per hour (both breasts), and this agreed pretty well with daily milk consumption as determined by weighing the baby when breastfeeding normally.  The paper is Lai et al., Breastfeeding Medicine vol 5 #3 p. 103, 2010.  Draining the breasts every hour takes out the variable of storage capacity.

I've developed a protocol based on this paper that I sometimes use as part of an assessment of milk production for mothers with non-gaining babies.  As Susan says, pumping should NEVER be used in isolation to measure milk production.  But used in context with other observations, I've found it can be helpful.  Especially for mothers with known IGT, BFAR, induced lactation, etc who want an additional indicator of whether what they are doing to increase supply is helping.  It can also be useful when baby isn't gaining well to get a sense of whether mom's supply is an issues (either primary or secondary to poor transfer), or whether it's really just a poor transfer problem.  I've found a couple of cases where the pumping test argued that mom's production was actually just fine, and so we could focus on why her breasts weren't getting drained.   I definitely wouldn't use this test in isolation, and I wouldn't use it unless mom is already doing some pumping and it's part of her preferred routine or her care plan.

Jessica 


Jessica Lang Kosa, PhD, IBCLC
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www.motherfeeding.com

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