Cytomegalovirus infection in preterm infants of gestational age <32 weeks or birth weight <1 500 g fed by their own mother's frozen breast milk / 中华围产医学杂志

ABSTRACT

Objective:To understand cytomegalovirus (CMV) infection status in hospitalized preterm infants who were fed by their own mother's frozen breast milk.Methods:This retrospective study enrolled breastfed neonates with gestational age less than 32 weeks or birth weight less than 1 500 g who were born and admitted to Gynecology and Obstetrics Hospital of Fudan University from January 2018 to December 2020. Clinical data of the babies and their mothers were collected and analyzed, including CMV DNA results of breast milk and urine samples of the subjects by fluorescence quantitative polymerase chain reaction. Chi-square test (or Fisher's exact probability test), two independent samples t test, and Mann-Whitney U test were used for the statistical analysis. Results:A total of 94 parturients and their 103 premature infants (including nine pairs of twins) were included. CMV DNA of breast milk was noted for positive in 75 cases (including eight pairs of twins) and for negative in 28 cases (including one pair of twins). Out of the 75 preterm infants born to mothers with positive CMV DNA breast milk, 67 (including eight pairs of twins) were switched to frozen breast milk (－20 ℃ for 72 h), and six of them were infected by CMV(9.0%) without any treatment. All of the 103 infants were divided into two groups the frozen milk fed group ( n=67) or fresh milk fed group ( n=36). In the frozen milk fed group, the CMV DNA was mainly detected during 2-8 weeks postpartum with copy number reaching the peak at 8th week. And those infants in the frozen milk fed group, whose mother's breast milk CMV DNA was positive, was further divided into CMV infected ( n=6) or CMV non-infected groups ( n=61) according to the urine test results. Moreover, compared with the non-infected group, the average [22.7(3.0-95.7)×10 3 copies/ml vs 5.0(0.5-89.5)×10 3 copies/ml, Z=－2.218) and the highest[45.9(5.9-261.0)×10 3 copies/ml vs 9.8(1.2-766.0)×10 3 copies/ml, Z=－2.218] copy number of CMV DNA in the breast milk were higher in the CMV infected group (both P<0.05). The incidence of feeding intolerance[37.3% (25/67) vs 50.0% (18/36), χ2=1.550], neonatal necrotizing enterocolitis [0.7% (1/67) vs 0.0% (0/36)], bronchopulmonary dysplasia [28.4% (19/67) vs 27.8% (10/36), χ2=0.004], retinopathy of prematurity [20.9% (14/67) vs 8.3%(3/36), χ2=2.682], and late-onset sepsis [22.4% (15/67) and 30.6% (11/36), χ2=0.828] did not differ significantly between the frozen or fresh milk fed groups (all P>0.05). Conclusions:The incidence of breast milk-related CMV infection in those fed with frozen breast milk was low and does not increase the without increasing risks of related complications or leading to obvious clinical manifestations after infection. For preterm infants with gestational age <32 weeks or birth weight <1 500 g, frozen breast milk can be an alternative for mothers with CMV DNA positive breast milk.