>>>One thing that still puzzles me - maybe you can help? When a baby goes
>through a growth spurt and feeds a lot more frequently, that induces
>hypothalamic prolactin release and increases milk production, right? So
>then the baby goes back to eating every 3 hrs or whatever and its
>increased needs are met by the increased basal rate of milk secretion.
>Yeah? So, my question is, what sustains this increased rate? Does
>prolactin keep being released at the increased level despite the
>back-to-normal suckling? Or, do the breasts make more milk in response
>to the usual levels of prolactin, this increased synthesis having been
>triggered by the little prolactin burst caused by the baby's increased
>feeding during the growth spurt?
>The reason I ask is, I was wondering why Reglan is tailed off again
>after 3 weeks. How is the milk supply kept at that high level? <<<

Peter Hartmann has studied this and found that there is actually *no*
increase in milk intake by the baby from 1 to 6 months - rather it is very
consistent. On the other hand, they found that the levels of prolactin
actually *fall* gradually over the months. The idea of prolactin being the
controlling factor for milk production is now out-of-date.

See: Cox DB, Owens RA & Hartmann PE, 1996, 'Blood and milk prolactin and
the rate of milk synthesis in women' Experimental Physiology 81: 1007-1020

It seems (my interpretation) that when a baby has a 'growth spurt', he may
temporarily eat more for a few days, but then drops back to the amount he
was taking before the 'growth spurt'. (A bit like a teenager who suddenly
eats everything in the pantry for a while, and then goes back to his normal
intake!).

Cox et al's conclusions were that prolactin is *not* controlling the amount
of milk produced at all. Once lactation is established, it is controlled
mainly by the autocrine system - the inhibitor in the milk in a 'full'
breast, which gives negative feedback to the breast to slow down
production. Each breast acts independently, so it cannot be controlled by
prolactin (endocrine) although they say that it is possible that a basal
level of prolactin *may* play a part in maintaining lactation.

I do not really know how all this relates to the tapering off of the
Reglan, except to assume that the Reglan helped boost the production in the
early days (when prolactin *is* important, when lactation is initially
turned on and being established), and now the breast is being drained well
and frequently by a vigorous baby, so helping the autocrine system to kick
in efficiently.

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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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