Jennie,

There is an older article in the New York State Journal of
Medicine, April 1984, (pp 169-173), entitled "Changing maternal and
newborn care -- a study of the Leboyer approach to childbirth
management", by Kliot & Silverstein.  It covers early vs late
clamping, and finds no differences in the health of the newborn
between the two methods.

I would also check the Oxford Database of Perinatal Trials, or the
print
version, Effective Care in Pregnancy and Childbirth.  There is a
particularly handy book which summarizes these two works called A
Guide to Effective Care in Pregnancy and Childbirth, by Enkin,
Keirse, and Chalmers (Oxford University Press).   I don't know if
this topic is covered (my copy is not handy), but it's the book I
would use if I had to confront HCP's over a particular form of care
-- it's very concise, scientific, and hard to refute.

Hope that helps,

Jennifer Landels