Hi all,
I emailed Peter Hartmann about our recent discussions concerning milk
supply, growth spurts, etc as well as the question about control at
different stages of lactation. He has given permission for me to share his
response with you all.

Peter wrote:
>I have been aware of these observations and have often wondered what a
>growth spurt really is.  A number of our studies show constant milk
>production over the first 6 months of lactation.  Although there is still
>quite a lot of variation with in mothers from one month to the next, there
>is no consistent increase at about 6 weeks.  There is no doubt that
>something is happening at this time but it may not be directly related to
>milk production.  Perhaps a developmental change in the baby that is not
>related to appetite.
>
>I think production for mothers expressing their milk is more irregular
>because it is more difficult to induce oxytocin release for expression,
>thus variation may be associated with stressful situations, or at least
>situations that result in poor milk ejection.  Thus I am not sure that the
>expressing situation and breastfeeding can be compared.
>
>The difference between early and late lactation is very interesting.
>Certainly things are somewhat different as far as control is concerned.
>However, I do feel that what is in the mothers mind is of great importance.
>In late lactation the mother is confident of her breastfeeding ability and
>thus normal physiological local controls can operate.  Early in lactation a
>mother who gives formula is not a confident mother and higher centre
>control may result in inhibition of lactation.
>
>I would be interested in any further comments and observations you have on
>these issues.

Next message:
>I don't mind if you forward my message to Lactnet.  I do seem to remember
>hearing somewhere that there were developmental changes in the baby that
>could account for the growth spurt idea but I can't recall the detail.

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Joy Anderson B.Sc. Dip.Ed. Grad.Dip.Med.Tech. IBCLC
Nursing Mothers' Association of Australia Breastfeeding Counsellor
Perth, Western Australia.   mailto:[log in to unmask]
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