Objective: We prospectively evaluated the rate of postnatal cytomegalovirus (CMV) transmission through breast milk in extremely premature infants to address the impact of CMV infection on preterm infants during lactation.
Study design: A total of 25 mothers and 27 infants (two sets of twins) with birth weights <1000 g and/or gestational ages <28 weeks were enrolled in the study. They were mostly fed frozen-thawed breast milk. Breast milk, serum and urine samples were collected every 2 weeks and screened for CMV infection using the real-time polymerase chain reaction.
Result: All of the 21 CMV-seropositive mothers had detectable CMV DNA in their breast milk, with a peak at 4 to 6 weeks postpartum. CMV infection was confirmed in only one infant (4.3%) who displayed almost no clinical symptoms.
Conclusion: At our institutes, we mainly use frozen-thawed breast milk. We found low CMV transmission rates even in extremely premature infants, and the CMV-positive infant did not develop serious symptoms.