Abstract: Objective To explore the clinical characteristics of neonatal congenital chylothorax (CC) and the high-risk factors affecting its prognosis. Methods The clinical data of children with CC admitted to the neonatal intensive care unit from January 2012 to May 2022 were retrospectively analyzed. Results Sixty children (36 boys and 24 girls) with CC were included, including 31 premature infants and 29 full-term infants. The gestational age was 36.7 (34.7-38.8) weeks, and the birth weight was 3160.0 (2755.0-3645.0) g. There were 52 cases of prenatal diagnosis of pleural effusion, 13 cases of intrauterine treatment, 31 cases of asphyxia at birth, 27 cases of intubation in the delivery room, 8 cases of pleural puncture during resuscitation, 30 cases of bilateral pleural effusion, 19 cases of fetal edema, 29 cases of hypoproteinemia, 14 cases of congenital chylous ascites, and 12 cases of congenital heart disease/chromosomal abnormalities. Compared with the full-term infant group, the preterm infant group had a lower male proportion, lower birth weight, higher rates of intrauterine treatment, fetal edema, asphyxia, intubation in the delivery room, mechanical ventilation, bilateral pleural effusion, albumin <30g/L, congenital chylous ascites and death, and the differences were significant (P<0.05). There were 49 children in the survival group and 11 in the death group. All the children died of respiratory failure within 1 week after birth. Binary logistic regression analysis showed that fetal edema was an independent risk factor for early neonatal death in children with CC (P<0.05). All children were treated conservatively and followed up. Three children were lost to follow-up, 1 relapsed, and the remaining 45 were in good condition. Conclusions Among neonates with CC, preterm infants are more likely to suffer from sphyxia, fetal edema, hypoproteinemia, bilateral pleural effusion, congenital chylous ascites, and the proportion of intubation in the delivery room, mechanical ventilation and death is higher than that of full-term infants. The CC neonates with fetal edema have an increased risk of early death. The long-term prognosis of children treated conservatively is good.

Key words: congenital chylothorax, clinical characteristics, risk factor, newborn