Pearl,

I don't have any references in front of me but I am a childbirth teacher and a
LLLL and from all of my reading on Rh factor the only problem comes from someone
who is Rh- getting any Rh+ blood, they will produce antibodies that would be
dangerous for the unborn baby during pregnancy (I don't know what applies to
men).  I know that the body's defense mechanism can cause problems, but only in
Rh- people.  That is why when blood is needed and the blood type and Rh factor
is not known they use O- (O being the universal donor, and Rh- to prevent any Rh
antibodies from being produced).  So if any of her Rh- negative blood mixes with
her baby's Rh+ (very doubtful from breastfeeding), it shouldn't bother the baby.
The risk comes if she gets any of her baby's blood in her blood stream (which
can happen when the placenta is delivered).

Hope this helps.

Felicia LLLL and MOM of 2