We have had this discussion before, and there is no "right" answer.
It had been felt that if a Mom was CMV positive she was excreting antibody as
well as virus in her BM, that the infant would be "infected" but have no long
term, serious sequellae. This holds true for full term and many preterm
infants, but apparently not for the VLBW infant.  A recent study (Vochem et
al. Pediatr Infect Dis J. 1998; 17:53-58) reports symptomatic CMV illness in
24-26 week infants fed their own mother's (who was CMV pos) BM. As the freeze-
thaw cycle will kill > 90% of CMV in BM we  (3 Neos- 2 who are IBCLC- and 4 ID
MDs) are working on a protocol for doing CMV testing on Moms of premies < 1200
gm (~ 29 wks) and using frozen milk until the infants are > or = 30 weeks, to
minimize the exposure. We are currently negotiating the gestational age and/or
birthweight we will use as the screen. I hate to do this, as my unit has had
only one case of symptomatic CMV in such an infant in the last 5 years, but
the local University NICU apparently has had several, and some infants died.
One of the problems is deciding what morbidity in a 24-26 week infant is due
to being a premie, and what is due to the CMV!
Nancy Wight MD, FAAP, IBCLC
Neonatologist
San Diego