[Analysis of the clinical features of postnatal cytomegalovirus infection in very preterm infants or very low birth weight infants].

<b>Objective:</b> To analyze the clinical features of postnatal cytomegalovirus (pCMV) infection in very preterm infants or very low birth weight infants. <b>Methods:</b> This was a case-control study. A total of 50 very preterm or very low birth weight infants who were hospitalized and diagnosed with pCMV infection in the Neonatal Intensive Care Unit of Children's Hospital, Zhejiang University School of Medicine from January 2019 to June 2024, were enrolled as the pCMV group. Meanwhile, through propensity score matching, each infant in the pCMV group was paired with a very preterm or very low birth weight infant without cytomegalovirus infection during the same period, constituting the control group, also consisting of 50 cases. Subsequently, the pCMV group was divided into a treated subgroup and an untreated subgroup according to antiviral treatment. Clinical data of all enrolled infants, including clinical features, laboratory test results, and clinical outcomes were collected. Differences in relevant parameters were analyzed using with <i>χ</i>² test or continuity-corrected <i>χ</i>² test or Fisher's exact test, independent-samples <i>t</i> test, Mann-Whitney <i>U</i> test as appropriate. Logistic regression was employed to analyze the risk factors, and Spearman correlation analysis was applied for non-normal distribution data or ordinal data. <b>Results:</b> There were no significant differences between the pCMV group and the control group in terms of gestational age, birth weight, proportion of male infants, Apgar score at the 1^st minute and 5^th minute and days of breastfeeding during the first 3 weeks of life (all <i>P</i>>0.05). Compared with the control group, the duration of hospital stay and invasive mechanical ventilation were both longer in the pCMV group (both <i>P</i><0.05). The risks of bronchopulmonary dysplasia, retinopathy of prematurity, and hearing impairment were all higher in the pCMV group when compared with the control group(all <i>P</i><0.05). The body weight and body length of the infants in the pCMV group were both lower than those of in the control group at the corrected gestational age of 36 weeks (both <i>P</i><0.05). pCMV infections were associated with the increased incidence of both necrotizing enterocolitis (<i>OR</i>=11.50, 95%<i>CI</i> 1.94-68.30, <i>P</i>=0.007) and severe intraventricular hemorrhage (<i>OR</i>=6.82, 95%<i>CI</i> 1.19-38.97, <i>P</i>=0.031) in very preterm infants or very low birth weight infants. In the treated group, the platelet count was significantly improved after 6-8 weeks of antiviral treatment compared with that before treatment ((245±19)×10⁹/L <i>vs.</i> (119±14)×10⁹/L,<i>t</i>=5.37,<i>P</i><0.001). <b>Conclusions:</b> Very preterm infants or very low birth weight infants with postnatal cytomegalovirus infection have longer hospital stay and duration of invasive mechanical ventilation, and are highly susceptible to bronchopulmonary dysplasia, retinopathy of prematurity, hearing impairment, and growth restriction. Antiviral treatment can effectively ameliorate thrombocytopenia in these infants.