Very low birth weight infants born to cytomegalovirus-seropositive mothers fed with their mother's milk: a prospective study.

OBJECTIVE: To assess the risk of post-natal cytomegalovirus (CMV) transmission to very low birth weight (VLBW) infants fed with their mother's fresh milk.

STUDY DESIGN: Prospective, observational study of 80 VLBW infants and their 68 mothers. Infants' urine and their own mother's fresh breast milk were tested for CMV by means of culture tests once a week until discharge. CMV in infected milk and urine were genotyped. The clinical course, laboratory findings, and outcome of infants infected with CMV at 2 years of age are reported.

RESULTS: Fifty-three mothers (78%) were CMV-seropositive at delivery. CMV was detected in the milk of 21 of 53 seropositive mothers (40%), and CMV was in the urine in 9 of 26 infants (35%) fed with CMV-positive milk. The same gN-genotype was found in milk and urine. Three infected infants <28 weeks gestational age (GA) had a mild sepsis-like illness. Five more infants had neutropenia, conjugated hyperbilirubinaemia, or both. Post-natal CMV infection occurred in 1 of 19 infants with a GA<28 weeks who were treated at birth with intravenous immunoglobulin versus 3 of 5 non-treated infants (P < .02). Symptomatic CMV infection was associated with bronchopulmonary dysplasia. No neurosensorial sequelae were found at 2 years of corrected age.

CONCLUSIONS: CMV infection via fresh human milk is mild, self-limiting, and without sequelae. Very-low GA and pre-existing chronic diseases are associated with symptomatic infection.