I have been following the retained placental fragments discussion with
interest, particularly the revelations about OBs and others not being aware
that retained placental fragments can inhibit lactation.  A little while ago
I had to explore this with an OB for a client, and dug up the following
info/references:

1.  Breastfeeding and Human Lactation p 357
2.  JHL Sept 92, p 153 (discusses over-supply, not under-supply, but
interesting)
3.  Linda J Smith's Lactnet post 24th July 1996, diagnosed by ultra-sound.
4.  BF: A Guide for the Med Profession, 3rd edition, p295 and p 376,
     gives journal reference p 418, # 75
5.  BF Management in Australia p 68
6.  Lactation: Physiology, Nutrition & BF, p 290 and pp 334-337
7.  Breastfeeding Answer Book (older version) p 225.
8.  LC Series 8, secondary factor, p 7
9.  Am J Obstet Gynecol June 15, 1981, "Failure of Lactogenesis
    associated with placental retention", Niefert, McDonough and Neville.

My observation is that delayed lactogenesis as a result of retained
placental fragments is not that unusual.  I frequently see moms at 2 or 3
days postpartum who are producing very scanty amounts of colostrum and are
concerned (naturally) about the baby's intake. I know that it can be
considered "normal" for good breastmilk production not to occur for 3 - 4
days, but I'm talking about *very* little colostrum being produced at this
time - manual expression produces tiny little droplets. Questioning reveals
that these moms have often passed small or large clots, or had a fairly
dramatic little episode of bleeding in the past 24 hours.  Breastmilk
production seems to increase to what I would expect to see on Day 2
post-partum within the next 24 hours, and then be on course from this point
onwards.  This even happens with mothers who have had C-sections.  Does
anyone else see this?  Or should I be looking for *another* explanation?
What I find quite magical about it though (as an example of how the human
body works so well, given half a chance) is that the baby is *hungry* - and
consequently wants to breastfeed *often*.  This would cause frequent
contraction of the uterus, which would result in expulsion of the fragments.

Pamela, Zimbabwe