Parenteral nutrition associated cholestasis ( PNAC) is a complication of premature infants caused by multiple factors and directly related to parenteral nutrition, resulting in multiple organ dysfunctions in premature infants. Long-term parenteral nutrition and intestinal failure are the main risk factors of PNAC. Its mechanism is complicated, and there is no effective prevention and control measures at present. This article mainly reviews the pathogenesis, risk factors and application of fish oil in PNAC.

Objective:To investigate the clinical features, influencing factors and outcome of cholestasis in preterm infants.Methods:The clinical data of premature infants(case group)admitted to the Neonatal Department of Shengjing Hospital of China Medical University and diagnosed with cholestasis from January 2016 to December 2018 were analyzed retrospectively.Non-cholestatic preterm infants who were hospitalized at the same time, with the same number, gestational age and birth weight were selected as the control group.The clinical data of the two groups were compared to understand the clinical features and risk factors of premature infant cholestasis, and to explore its influence on the development of premature infants.Results:The total cases were 112(the ratio of male to female is 2.02). The gestational age ranged from 25 to 36 weeks, the median gestational age(interquartile interval)was 30(28, 31)weeks, and the gestational age <32 weeks accounted for 78%.The birth weight was 440 to 3 840 g, the median birth weight(interquartile interval)was 1 142(979, 1 300)g, and the birth weight <1 500 g accounted for 83%.The duration of parenteral nutrition, hospital stay, beginning enteral feeding, and reaching total enteral feeding in the case group were 37 d, 62 d, 5 d, and 37 d, respectively, while those in the control group were 23 d, 45 d, 4 d, and 22 d, respectively, with statistical significance( P<0.05). The incidence of necrotizing enterocolitis, patent ductus arteriosus and extrauterine growth retardation in the case group was 16.1%, 15.2% and 91.2%, respectively, while the incidence of corresponding diseases in the control group was 4.5%, 6.1% and 83%, with statistical significance between the two groups( P<0.05). The rate of weight gain after cholestasis was 8 g/(kg·d)in the case group and 13 g/(kg·d)in the control group, and the difference between the two groups was statistically significant( P<0.05). Logistic regression analysis showed that prolonged parenteral nutrition was an independent risk factor for cholestasis in preterm infants. Conclusion:Cholestasis in preterm infants is more common in ultrafast preterm infants and early preterm infants or in infants with extremly low or very low birth weight.The incidence of was increased with cholestasis, and the length of hospital stay was prolonged.Prolonged parenteral nutrition is an independent risk factor for cholestasis in preterm infants.