Alicia,
The sodium content of milk increases during rapid weaning as the
activity of the alveolar cells decreases and sodium replaces lactose in
the milk due to decreased rate of lactose synthesis, resulting in
osmotic pressure that pulls the sodium into the milk.  Toddlers who are
weaning gradually often skip a few days or even weeks, and then nurse to
find the milk sweet, not salty.  I don't think child-led weaning has ever
really been studied, but I suspect that the mom gets really good at
maintaining lactose levels even with infrequent milk removal.  Possibly
due to the development of prolactin receptors in the alveolar cells,
which allow tiny amounts of prolactin to be effective in catalizing the
formation of abundant lactose... (analogous to the oxytocin receptors
that proliferate in the uterus at term and the resultant dose of pitocin
needed....) It is hypothesized that these receptors form in response to
milk demand in the first 6 weeks postpartum.  So I would say that a mom
should optimally try for complete breastfeeding for that long, and then
gradually decrease to the desired number of feeds... I have seen moms
of 3 or 4 month old babies who were able to maintain lactation on just
one feeding per day.  The above is just my speculation on this issue...
Catherine Watson Genna, IBCLC  NYC  [log in to unmask]