Transmission of cytomegalovirus to extremely preterm infants through breast milk

AIM: To evaluate the rate and clinical expression of postnatal cytomegalovirus (CMV) infection transmitted through breast milk in extremely preterm infants. METHODS: Ten extremely preterm infants and their six mothers were included. Maternal CMV serology was determined. Breast milk samples and urine samples from the infants were screened for CMV. Symptoms and laboratory findings of CMV infected infants were documented. All infants received partly fresh and/or defrosted breast milk. RESULTS: CMV-DNA was found in breast milk in four of five CMV-seropositive mothers. Two infants were infected by CMV. They were the only infants fed with breast milk positive for viral culture. One infant developed hepatic affection concurrent with viral excretion in urine. This infant was later diagnosed with cystic fibrosis. CONCLUSION: This study supports that CMV transmission through breast milk can aggravate the clinical course in extremely preterm infants with preexisting hepatic conditions.