Subjects & sub-grouping
death
-20, CRITICAL ILLNESS, CONGENITAL CMV INFECTION
Neonates born with a gestational age (GA) < 32 weeks or birth weight (BW) < 1500 g between April 2015 and January 2019 and whose mother’s HM showed positive results of CMV in culture or polymerase chain reaction (PCR) within 7 days after birth were enrolled. The exclusion criteria were congenital CMV infection, death within four weeks of age, critical illness, transfer out, unavailable HM supply by the mother. The enrolled infants were randomized into three subgroups according to the HM preparation methods: the freeze-thawing (FT) group, FT + low-temperature Holder pasteurization (FT + LP) group, and the FT + high-temperature short-term pasteurization (FT + HP) group. Specifically, infants in the FT group were fed their mother’s own HM that had been stored at -20 °C for more than three days. Infants in the FT + LP group were fed mother’s own HM that had been conventionally pasteurized at 62.5 °C for 30 min after thawing. Infants in the FT + HP group were fed HM that had been pasteurized at 72 °C for 5 s after thawing. After heating in a shaking water bath (BS-11, Jeio Tech, Korea), the HM was directly immersed in iced water for 15 min until the temperature reached 10.0 °C, and the HM was stored in a refrigerator; the heating treatment was carried out by one designated research nurse at each hospital using the same protocol. The randomization was performed at the Department of Clinical Epidemiology and Biostatistics at Asan Medical Center.