Other questions I have:  How does this apply to the transfer of drugs into
milk? I have operated under the belief that much of the milk is made at the
time of nursing/pumping, and that the blood levels at that time are important
for determining transfer. Do we not tell mothers to time their doses
accordingly to minimize transfer? And yet, Peter Hartmann's research suggests
to me that milk is synthesized continuously at more constant, though
changing, rates, depending upon current milk volume!  I had a picture in my
mind of synthesis between feedings as being very low, and synthesis at MER as
kicking into high gear. Rather, it would appear from Peter's notes that
synthesis is occuring at its own rate, and that the only reason a small
amount--- foremilk--- is collecting in the off times is because there is no
action to push the milk down. Thus, much of the milk *is* supposedly produced
between feeds and  remains stored in the alveoli until oxytocin pushes it and
especially the fat down during MER.   Should this change the way we view drug
transfer into milk, and how we advise mothers?  Moreover, maybe Peter's
research explains why we have widely varying anecdotal reports on the
transfer of some drugs into human milk with specific moms.

Now, what is there to say about multiple MER's?  Are they more frequent in
women with smaller storage capacities not only because they don't store as
much at one time, but because perhaps the rate of sythesis remains higher for
them because complete emptying occurs sooner and more frequently? Do they
actually have more milk to "let down" because they are producing it more
quickly than mothers with large capacities?  Does this explain the varying
MER patterns that we see with women?

Other facts gleaned from the lecture:

-Human Placental Lactogen correlated to growth in breast size during
 pregnancy. Peter noted that there were some women who *did not* show much
initial growth, but who actually "finished" growing in the  early pp period!

-Human milk not just a food; also complements immaturity of organs in
 infants

-Lactogenesis occurs between 30-40 hrs from withdrawal of progesterone,
 which is removal of placenta

-It is the large protein of casein that makes cow's milk look "thicker" and
 more substantial than human milk (there's that normalizing the  abnormal
again!)

-"Quiescent" cells---> reserve cells that may not always be in use for milk
 production, but may be recruited later on down the line. (Does this  perhaps
explain the dilemma of relactation? Do some women have  these extra cells,
and others not, to call on after involution of primary cells?)

-Massage of breast before feeding can help to get more fat into the initial
milk

Alright, Ladies and Gentleman, get to work! I'm looking forward to your
reactions and thoughts.

-Lisa Marasco, IBCLC
[log in to unmask]@slonet.org