Transmission of cytomegalovirus via breast milk in low birth weight and premature infants: a systematic review and meta-analysis

Background This study aimed to investigate the transmission of cytomegalovirus (CMV) via breast milk in low birth weight (LBW) and premature infants and its effects. Methods PubMed, Medline, Cochrane Library, and Embase were searched for studies (without language and time restriction) published before March 27, 2020, that examined the effect of CMV transmitted by breast milk on LBW and premature infants. The rates of breast milk-acquired CMV infection, CMV-related symptoms, and CMV-related sepsis-like syndrome (CMV-SLS) in LBW and premature infants were pooled from each study. Results Eighteen studies with 1920 LBW and premature infants were included. The pooled CMV infection rate from breast milk for infants fed untreated breast milk was significantly higher than those fed frozen breast milk [19.3, 95% confidence interval (CI) = 11.8–29.9% vs. 13.5, 95% CI = 8.0–22.0%, P < 0.01). Similarly, the pooled CMV infection rate for infants fed untreated breast milk was significantly higher than those with mixed feeding ( P < 0.0001). The mixed feeding group had a significantly lower rate of CMV-related symptoms than the other groups (2.4%, P < 0.01). Conclusions These findings suggested a higher CMV infection rate in LBW or premature infants fed untreated breast milk than other feeding groups. Studies on the long-term outcomes of CMV infection transmitted from breast milk are needed to address the optimal feeding practice.