Ruth Lawrence supports bf a baby with CF.  Check  the 4th edition, p 441-2,
for info and references.  The new Riordan/Auerbach has a good section on bf
babies with CF, p 655.  "There is no need to interrupt bf.  In fact, bf is
recommended."  They state that the lipase in human milk may help the infant
with CF absorb fat better.  They quote three studies that showed bf infants
with CF developed symptoms only after they were weaned.  BF infants were
taller and heavier than AF infants.  BF also provided protection against
respiratory illness.
Cynthia D. Payne
LLL of Berkshire County Massachusetts