I may have no case studies.  But I have worked in a hospital in L&D and postpartum for 21 years.  I have been cupfeeding infants  for longer than that, starting with my own premie, 25 years ago.    I have seen babies who did better with a cup than with either breast or bottle.  I have seen all three types of babies try inhale the substance they were drinking.  And I've seen all three types of babies succeed in aspirating.  Some of these babies later ended up in NICU for neuro problems, TE fistulae or reflux problems, infection and whatever else was not easily observable at birth.  But none of them died from the cupfeeding itself.  In fact, none of them died that I know of, as a consequence of that aspiration.

If I can't prove the long-term aspiration effects of breast vs. bottle  vs. cup, neither can you.  As you say, the research doesn't exist.   And it seems the issue of what they aspirated has to come in there.   Do your case studies tell you what the babies aspirated, or how they were fed?  I think mother's milk has to be far less noxious than any "other stuff."

 I think most of the literature related to aspiration, that you are reading, has to come from babies who were bottlefed formula, since that is how the majority of women through out the country have fed their babies for the past 50 years.   Perhaps studies are needed  dividing the aspirators into two groups:  human milk vs. other concoctions.  And then those groups subdivided:  Human milk -- breast, bottle or cup;  other -- bottle or cup.  

Recent research in   breastfeeding has taught us more and more about what babies are able to do. We've seen that younger and younger premature babies can breastfeed -- as some have said "they didn't know they couldn't do it."   I would suggest that your < 4 mos. guidelines re cupfeeding may need some new research.

You mentioned in one of your posts the studies on the necrosis "discovered" on autopsy.  Does this mean the infants demised for other reasons than the aspiration, and the necrosis was found as a concommitant event, not a causative event?  (For instance, I know that autopsies on adult males over 55, who died for other causes, show a large percentage of prostate cancers; while the men themselves, according to those who knew them, had no sxs or complaints.)

A thought that has crossed my mind several times since you started 
asking questions.  Could it be that the newer born an infant is, the easier it
 is to learn to cup feed, because he still hasn't really mobilized all his 
feeding responses, and so more readily adapts to whatever system is 
being used?  I have seen very voracious breastfeeders who had no use 
for a cup, and didn't want to learn without good reason.  Alternatively, I 
have seen infants unable to latch, with a disorganized bottle  suck, who 
took to cups instantly.

I  have to ask.  How many babies have you SEEN breast/bottle or 
cupfeeding?    This is not meant as a put-down.  But once you have seen 
a newborn cupfeeding, you can no longer say they aren't capable of 
doing that at less than 4 months.  The question becomes, why does the 
literature say he can't?  And have you only read the literature done be people in your profession, or does it include review of all breastfeeding literature.

I am glad you are asking questions and willing to learn from our collective
expertise of both BF literature and experience.  But why are you so 
combative in your questions?  It seems as if you feel a threat, either 
personal or professional, from the fact that babies can cupfeed. The 
scientific method is to form a theory, then design experiments that 
prove it.   There are a lot of experiments that yield results different than the
 ones expected.   Often because of  variables included or not.  But 
sometimes the basic premise is wrong.

A cartoon in my mind's eye:  Einstein scratching his head looking at a 
mom cupfeeding her newborn, and saying :
                   "Vell, I see ve vere wronk.  Zey ken do zat!"

So now Goeff, the ball is back in your court.  Serve!

Chanita, San Francisco