The excretion of CMV in the milk of cytomegalovirus (CMV) IgG-positive mothers is a common phenomenon, mostly intermittent. CMV is detected in 80% to 97.2% of breast milk if the milk is monitored several times in a row.The peak of CMV excretion in breast milk is 4-6 weeks after delivery, and the proportion of infections acquired during breastfeeding for more than 1 month is significantly higher. Current studies have confirmed that CMV infection in postnatal infants originates primarily from breast milk containing CMV. Perinatal and postnatal CMV infections are benign, self-limiting diseases with no significant near- or long-term effects on term infants. A multicenter study in Beijing in which our hospital participated showed that 20.27% of infants were infected with CMV during the perinatal period and 66.69% were infected at the age of 1 year, and the difference in clinical manifestations between CMV-infected and uninfected infants was not statistically significant, confirming that perinatal and postnatal CMV infections do not have any significant effect on growth and development. Breast milk contains appropriate nutrients and rich immunologically active substances, which are the important material basis for resisting the attack of pathogenic bacteria, and is the most ideal food for infants. Although there is a risk of perinatal CMV infection, the benefits still outweigh the disadvantages relative to the growth and development of infants and the reduction of serious diseases. And China’s women of childbearing age CMV lgG positive accounted for more than 90%, most mothers during breastfeeding there is the possibility of detoxification in breast milk, in the existing conditions hope to completely avoid CMV in breast milk is difficult to achieve, so for healthy full-term infants, even if breast milk CMV-positive, you can still continue to breastfeeding, and generally does not cause significant impact on the infant. It is important to note that preterm infants delivered by CMV IgG-negative mothers and very low birth weight infants delivered by CMV IgG-positive mothers develop perinatal CMV infection. Serious pathology may occur. CMV infection has been observed in 38% of very-low-birth-weight infants from the breast milk of seropositive mothers, 48% of whom were symptomatically infected and presented with a CMV “sepsis-like syndrome,” with clinical manifestations that included hepatosplenomegaly, apnea, bradycardia, intestinal flatulence, pallor, leukopenia, and thrombocytopenia. In view of the danger of perinatal infections to very low birth weight infants, many experts suggest that feeding very low birth weight infants the milk of IgG positive mothers after pasteurization or freezing at one 20°C can reduce the activity of CMV. There are many similar reports from abroad, but the results are not consistent and further studies are needed.