>Furthermore, it has been stated that the majority of milk is produced
*during* a
>feeding, which would follow if the prolactin is released during suckling and

is
>necessary for milk production.
>
>So, the question is...why do women become full between feedings (or
over-full
if a
>feeding is skipped)?  If there is no baby at the breast, there is no release

of
>prolactin and, therefore, no production of milk.  Where is that milk coming
from?

Kathy, et all--
Your assertion that milk is produced primarily during a feeding is what
was believed before the advent of Peter Hartmann's work.  His research
has shown that milk is sythesized continuously, and that the "emptier"
the breast, the faster the rate of synthesis, and vice versa.  Check out
Hartmann's articles in JHL of the past year or two for more on this---
JHL is also testable material.  This seems to explain why breasts "fill
up". Another interesting component to his studies was the finding that
breasts appear to act like storage tanks, and that the capacity for
storage varies quite a bit from one woman to the next (he found a 3 fold
difference in his study). This piece of information explains to me why
some women can pump a large amount of milk, while other mothers can pump
only a feeding's worth.

As for the relationship of prolactin to milk production-- Hartmann's work
ties in with the theory of autocrine control of lactation after the first
3-4 mos.  Check out Riordan and Auerbach on this, (I believe it's page
87-8 or around there: the prolactin receptor theory).  Prolactin levels
are high the first three months, but gradually decline and then plateau
at a lower level thereafter. Thus, we know that prolactin is not the only
component to milk production, and also seems to be less important after
the first few months. Rather, the number of prolactin *receptors*
developed during the first few months appear to be the key issue, and
frequency of feeds seems to optimize adequate development.

-Lisa Marasco, BA, IBCLC

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         Lisa Marasco, BA, IBCLC
    Expressly Yours Lactation Services
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