Dear Ann Altshuler,
I attended a meeting in Chicago in Feb. 95 on the subject of breast
cancer during preg. and lact.  Several of the presenters commented
on reduced capacity for milk production in a breast treated with
lumpectomy and radiation.  Sometimes, there was no lactational
function at all after this type of treatment.  Watching for changes (growth)
of the breast during preg. might tell you if there was glandular activity.
The untreated breast should function normally.  I have worked with a
mother who successfully lactated for a 4th child following full mastectomy of
her left breast.  There was an excellent bibliography provided by Rush-St
Luke's-
Presbyterian (the sponsor of the meeting.)  I will try to post a couple of
the
references in the next day or two once I hunt them up.
Barbara Wilson-Clay,BS,IBCLC, private practice, Austin,Tx