At our Branch Conferences for NMAA (Nursing Mothers' Association of
Australia) which I have been attending for 8 years, I can't recall once
where babies were a problem.  It is just assumed they will be there.
Two creches are provided, one for babies and one for toddlers.  These are
staffed by Trainee Breastfeeding Counsellors on a roster basis (the payoff
is they are allowed to sit in on one Conference session if they volunteer to
do this job) and child care students (who are required to fulfill a certain
number of practical hours before they can achieve their qualification). It
is up to each individual mother when and if she leaves her child in the creche.
When a baby needs its mother, one of the creche workers comes silently into
the conference room and holds up a big sign bearing the mother's surname so
she knows she's needed.
Incidentally, our Conference venues are very downmarket, the cheapest we can
afford where we all fit. No Hiltons or Raddisons I'm afraid.  I'm
desperately jealous.

Lesley McBurney, Brisbane, Oz