Pat says:

<My understanding is that the milk  on the 2nd side is sort of homogenized 
because  let down hits both breasts.  If baby doesn't take 2 nd side, my 
understanding is that fats are gradually reaborbed and milk is back to 
"fore" milk  status. >

Another "history lesson", I suppose;-) My reasoning stems from my experience when my mom was young and grandma was often there to "help out". Pasteurized, but unhomogenized bovine milk was delivered in quart glass bottles, to the porch. They had been kept cold by being surrounded by ice chips in the iced containers in the milk man's truck. The cream was always obvious at the top of the bottle. 


Back to 1933-34 when few women worked outside the home, my grandmother first poured off most of the cream to save for use in coffee (or maybe even whipping, cream for desserts???) I remember as a 3-4 y.o. the long stays at the breakfast table when I stubbornly refused to complete eating my cereal due to the "blue milk". I belonged to a "Children are to be seen and not heard, do-as-I-say and clean-your-plate family.



(Several years in the future, we received insulated milk boxes to keep on the porch. I still remember these when my own kids were preschoolers in the 1950's!!  The weather, summer or winter especially, must have been a very important motivation to wait and watch for the milkman!!)


(Many, many years later I learned that the specific gravity of cream is less (lighter) than that of skim milk, so the heavier fluid of the non-fat portion stays downward toward the center of the earth while the droplets of cream separate and float upward "toward the sky [or ceiling]" simply by their different specific gravities. I reason that this basic physical fact of specific gravity also must apply at least in part to the action of fat seen on ultrasound after the relaxation/readjustment of the cylindrical measuremetnts of the ducts taking place following MER. The same phenomenon would effect either the completely unremoved milk in the opposite breast being ultrasounded during feeding, or also after partial milk removal.)


So to Pat's analysis, I am adding what I imagine to be going on.


Rather than "sort of homogenized", I would stay instead, say "well-mixed, when the creamier milk from the milk closest to the ceiling is "rocketed forward" with the rest of the milk in the ducts when MER hits both breasts. (Therefore, if mom has been sitting or standing upright for most of 16 hours, it has risen to the top or uppermost parts of the ducts, which roughly corresponds to the "back of the breast". However, if she has been lying down 2+ hours or more, in my imagination, I see "toward the ceiling" as the upper side of most of the ducts front and back in the breast: e.g. if she is lying on her right side, the cream is on the left side all along the ducts, front as well as back ducts, so even if the milk is removed between MER"s, maybe the cream is closer to exiting the nipple than if mom had been upright for hours??? 


I digress;-)



<baby doesn't take 2 nd side, my understanding is that fats are gradually reab(s)orbed and milk is back to 
"fore" milk  status. >


Rather than reabsorbed, re-distributed, as the fat globules separate themselves from the non-fat portions as I explained above, partly dependent on whether mom is upright or lying down for several hours since the last MER.


Or as Heather explains, frequent nursing and therefore frequent MER's in whatever position is mixing the fat globules with the non-fat portions in varying proportions in both breasts throughout the 24 hour day, so letting the baby "finish" (or soften, from a perspective that mom can sense with her own senses rather than have to anxiously(?) interpret from baby's behavior) the first breast, gives the baby the thirst-quenching benefits of foremilk plus much of the digestion slowing action and high-caloric value of the hindmilk from the first breast. 


And then from the "second  breast" (or "third breast, etc.) whatever extra "still thoroughly blended" milk is currently available close to the front of the other breast, while nature is busy manufacturing fresh milk at dissimilar speeds further back in the glandular portion of each individual breast. 


Thanks for listening, all of you, while I have permitted myself "go out to play" on LN, in the midst of a list of "must do" tasks before leaving for ILCA Wednesday;-) Sigh! Back to the list to finish crossing off  tasks!!


K. Jean Cotterman RNC-E, IBCLC
WIC Volunteer LC     Dayton OH

 

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