Zab writes:

<Recent research from the Hartmann Human Lactation Group, has now
revealed 
that humans do not have Lactiferous sinuses/cisterns. Instead, milk 
removal from the breast is dependent on the positive pressure caused by 
the Milk Ejection Reflex (MER), corresponding duct dilation and the 
negative pressure achieved by the infant's seal on the breast. Milk 
transfer thus only occurs in significant volumes during the MER.
(Ramsay, Kent, Owens, Hartmann. Ultrasound Imaging of MER in the Breast
of 
Lactating Women. Pediatrics 2004;113;361-67) . . . . 

Without sinuses to massage(!!!)what is the physiological reason for 
hand expression being the most effective technique for obtaining 
colostrum?  

It makes me miss those lactiferous sinuses!>

Congratulations on your success in teaching hand expression to staff and
mothers! I am guessing that a great many of your mothers birth with a
minimum of obstetric intervention compared to U.S. moms. How much better
it would be if more mothers were taught in the hospital! 


Don't despair, Zab, lactiferous sinuses are still there clinically, and
many of us are here to testify to that! IME, they can be palpated in most
mothers by late third trimester of pregnancy. At times, when teaching a
mother to hand express in our WIC office, depending on whether she is
past the engorgement stage and in full production, and how large her
particular sinuses, or subareolar ducts or whatever you want to call
them, happen to be, it is possible in some moms to squirt streams 3 feet
out in front of her, before her MER has a chance to be triggered! But the
fingers must be positioned just right, and the direction of the
finger/thumb motion/pressure must begin precisely behind the sinuses for
it to happen. There is a technique to it. And Chele Marmet's technique,
available in tear-off sheets from LLL, tells it just like it is! While I
may be about the only one who has been so publicly vocal about it, I bet
there are countless LC's and LLL's and nurses who still believe that's
what they are palpating when they express efficiently! As Shakespeare
said, a rose by any other name smells the same. This has a very definite
effect on the size pump flange that will be efficient for a particular
breast in a particular mom, also.


I have several times questioned Dr. Hartmann personally on this since
these findings first began to be presented. His words were "We are unable
to demonstrate the presence of lactiferous sinuses on ultrasound." To me,
that's a clever way of phrasing the findings, and doesn't equate to
"There are no lactiferous sinuses", as the others seem to be concluding.
I can buy his phrasing, for several reasons. 


#1) the errors in our perception are the fault of the cartoonish
diagrammatic illustrations that have evolved over the years. I think it's
our perceptions that need to change. The largest lactiferous sinuses I
have ever palpated have never been larger than one-fourth the size of a
woman's little fingernail, which is much smaller than we are accustomed
to imagine from the diagrams that are themselves, smaller than life-size.
I would compare what I often feel to the size of tiny lumps in tapioca
pudding, or bee-bee shot. 


#2) we are familiar with the fact that all other reproductive organs
(male and female) change size, shape, consistency and to some degree,
location, during various phases of reproduction. Why should we be
surprised that lactiferous sinuses would also go through some changes?
The histologists and breast surgeons, as well as radiologists, have been
describing lactiferous sinuses in the resting breast for decades, and in
fact, that anatomical name is part of official histological nomenclature,
because precise terminology is very important in clinical communication
about breast disease. They are present in men, as well as children, but
only the adult female has a thick wall of elastic tissue around each
sinus. (references available) If they are so specially identifiable in
shape and character in the resting breast, what reason would nature have
for making them "disappear" completely in the lactating breast?? Perhaps
it's because they only "morph" temporarily during lactation, in ways that
can't be scrutinized by ultrasound, only by microscope????  However,
until we can get pathologists, and in particular, forensic pathologists,
interested in contributing to this debate by examination of surgical or
post-mortem specimens of breasts in various stages of pregnancy or
lactation, we have no way of proving it under the microscope. Palpation
will have to do among those of us who still "keep the faith" in the
existence of lactiferous sinuses, especially in the pregnant and
lactating breast.  


As to some of your other questions:
<What determines the volume of colostrum produced during pregnancy?>
I can't give a reference other than clinical experience for most of this
answer. I do suspect that some mothers have more milk making tissue than
others, and therefore, the number of sinuses under the areola differs.
Even the non-pregnant breast produces secretions during the menstrual
cycle. Gradual production of colostrum itself is said to begin to take
place after mid pregnancy. If a mother has shallow sinuses, quite close
to the nipple surface, even the stimulation of the bedsheets may
sometimes evoke MER's and cause her to leak at night during the third
trimester. The "cure" is to have her wear a sleep bra. My theory is that
during Braxton Hicks contractions droplets are gradually pushed forward
in the dilatable ductal system till they reach the endpoint of the more
easily dilatable ductal structures, i.e. the sinuses, and the flow is
usually stopped by the different kind of cell lining (less expandable)
and squamous cell debris in the galactophores in the more well-everted
nipple. I envision that continued production begins to cause slight
expansion of the elastic walls of the sinuses till they can be palpated
in well over 50-75%  of mothers in the late third trimester. I have
palpated sinuses in literally hundreds of mothers during (voluntary)
nipple function assessments/skill teaching sessions during 20 years of
caring for prenatal patients in public health and CEA breastfeeding
classes.


<What is the role of the MER in removal of colostrum immediately post 
partum? (Instead of "pressing" the milk out of the sinuses as previously 
thought, are we simply stimulating an MER when we hand express?)>


IME, the MER is not yet conditioned in many first-time nursing mothers,
and even in experienced nursing mothers, begins gradually, gentle at
first, because there is less fullness. My observation, off the top of my
head is that slight leakage or easy flow as evidence that the MER has
happened takes about 30-60 seconds to make itself known after manual
stimulation. I think I see some correlation between the observed strength
of the MER with the actual fullness of the breast (e.g. the less full the
ducts, the less obvious that the signs will be seen by HCP's and felt by
the mother, though it is still effective in propelling milk forward. And
vice-versa, the fuller the breast, the more obvious the signs often are,
as in overactive MER by about 2-3 weeks in some moms. I sometimes wonder
whether the amount of intrapartum pitocin given may be occupying binding
sites. However, direct stimulation of the nerves near the central areola
may directly elicit MER without oxytocin release, at least in the ductal
system of the anterior breast, by a mechanism known in agriculture as the
Tap Reflex (calves and kids butting dairy animals' udders cause this.) So
hand expression, as well as reverse pressure softening, does trigger MER.
Just usually gentle ones till obvious ductal filling occurs. But if
fingertips are in the right place, manual expression can produce results
before the MER is fully triggered. It just produces results more easily
once the MER has begun to occur.


<Assuming a good hand expressing technique, what accounts for the
variation in women's success in hand expressing colostrum? (some women
get 2 drops, whilst others get many mls!!)Is it variations in volume, 
effectiveness of the MER,both .....or is there some other physiological
reason?>


For starters, I have found that sinuses are not always at the same depth,
even in the two breasts of the same mother. If the sinuses are shallowly
placed behind the nipple, they are easily reached, and more efficiently
expressed (as in the example of prenatal leakage cited above). However,
if they are quite deep, it is difficult (and often uncomfortable) to get
behind the sinuses in order to treat them like "tiny toothpaste tubes" as
I like to describe them to moms. Therefore, it may not be possible to
express (or pump, or for the baby to strip) much milk forward until the
volume builds up and expands the sinuses more. OTOH, some moms just don't
seem to have very much collected in the anterior ducts by birth. And
depending on how much IV fluid/overhydration the mom may have, edema in
the connective tissues may limit the efficiency of hand expression by
blocking access to the sinuses. And in the case of such interventions,
pumping has the potential to make the degree of edema in the
nipple-areolar complex even worse! But that's another subject.

Can you tell that this subject pushes my buttons! Having read quite a bit
on embryology and histology of the breast, my conclusions are evidence
based enough for me-especially the ones gained by evidence from my own
fingertips and eyes!

Jean
**********************
K. Jean Cotterman RNC, IBCLC
Dayton, OH USA

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