Cytomegalovirus (CMV)
Maternal Infections Cytomegalovirus (CMV)

Cytomegalovirus (CMV)

Cytomegalovirus is considered a ubiquitous infection among humans. In the USA approximately 40-60% of mothers are CMV-seropositive, which means that they carry the virus. CMV is spread thru bodily fluids, including breastmilk. Perinatal transmission can also occur during pregnancy, and labor & delivery. Approximately 27% of CMV-seropositive mothers shed the CMV virus in their breastmilk. Term healthy newborn infants are at minimal risk for significant illness from CMV exposure1, whereas very premature infants born before 30 weeks have a higher risk of significant illness from CMV infection1,2.

Most neonatal intensive care units in the USA do not screen breastmilk for the presence of the CMV virus. Freezing/thawing of breastmilk helps to diminish transmission of CMV from breastmilk. Pasteurized banked donor milk is free of CMV virus.


  1. Bardanzellu F, Fanos V, Reali A. Human Breast Milk Acquired Cytomegalovirus Infection: Uncertainties, Doubts, and Perspectives Current Ped Rev 2019 15, 30-41
  2. Lanzieri TM, Dollard C, Josephson CD, Schmid DS, Bialek SR. Breastmilk acquired cytomegalovirus infection and disease in VLBW and premature infants Pediatrics 2013 June; 131(6): e1937-45