The short-term pasteurization of breast milk from mothers with cytomegalovirus (CMV) significantly decreased CMV infections in very preterm infants, according to data published in Clinical Infectious Diseases ( identifier: NCT01178905).

Using polymerase chain reaction and short-term urine microculture the CMV status of infants at discharge was determined in 87 preterm infants weighing <1500 g or with gestational age <32 weeks of 69 CMV-IgG-positive mothers. A group of 83 historical controls was also included in the study. The breast milk samples were pasteurized (62°C for 5 seconds) from postnatal day 4 to discharge.

Postnatal CMV transmission occurred in 2.3% of the 87 study infants compared with 20.5 % of controls. Calculated incidence rates for test and control infants were 0.21/year (95% CI, 0.03/year-0.75/year) and 1.70/year (95% CI, 0.99/year-2.72/year), respectively.  The risk ratio between controls and study infants was 8.3 (95% CI, 2.4-52.4; P =.0003).

In addition to its use of historical controls, the study was limited in that no data on bronchopulmonary dysplasia or neurodevelopment was available for comparison between the cohorts due to changes in definitions and instruments over time. Also, although unlikely, the loss of equipoise regarding the need for CMV reactivation may have introduced bias.

Study investigators concluded that short-term pasteurization “is an effective method for significantly reducing postnatal CMV infection rates in the [neonatal intensive care unit].” However, they also acknowledged that the method is time-consuming and requires precise pre-processing and constant training of nursing staff. Therefore, they suggested that “these efforts have to be balanced against the well-known short- and long-term adverse sequelae of postnatal CMV infection in very preterm infants.”

Related Articles


Bapistella S, Hamprecht K, Thomas W, et al. Short-term pasteurization of breast milk to prevent postnatal cytomegalovirus transmission in very preterm infants [published online November 8, 2018]. Clin Infect Dis. doi:10.1093/cid/ciy945