Thanks, Joy....you are right that it is more accurate to say that it's the
milk hanging about in the breast that *prevents* milk synthesis. But I
still don't think this tells the whole story - unless I am mising
something.

I still wish we had a good way to explain to mothers, and ourselves, what
precisely happens to make it possible to feed an older baby or toddler only
once or twice a day, and still always have milk available, even when that
same child ups his demands for some reason, while trying to do this to a
newborn or younger baby (without expressing in between) would simply mean
your milk supply would tail off

Mothers who return to work when their babies are (say) six months old can
feed  morning and evening (and probably night) Monday to Friday, without
expressing in the day, and then feed ad lib Saturday and Sunday. They feel
full on Monday, but settle down by Wednesday and Thursday.

Why?  I realise that leaving long intervals between feeds slows down milk
synthesis and feeding frequently speeds it up...but why can you go long
intervals when your baby is six months, and not when your baby is six
weeks?  I assume there is a spectrum of experience here - some women go
back to work when their baby is four or five months and have few  problems
maintaining a supply, others report their supply dwindles. Generally,
though, the later the better.

Heather Welford Neil
NCT bfc, Newcastle upon Tyne UK