目的 探讨极/超低出生体重早产儿早发型坏死性小肠结肠炎（necrotizing enterocolitis，NEC）的临床特征及危险因素。 方法 回顾性分析2014年1月—2021年12月郑州大学附属儿童医院收治的194例极/超低出生体重早产儿NEC病例的临床资料。按照NEC发病时间不同分为早发型（<14日龄发病，n=62）及晚发型两组（≥14日龄发病，n=132），比较两组围生期情况、临床特征、实验室检查结果、临床结局等。选择与这些NEC早产儿同期住院的，且胎龄和出生体重与之相近的非NEC患儿62例为对照组。采用多因素logistic回归分析探讨早发型NEC发生的危险因素。 结果 早发型组1 min Apgar评分≤3分、Ⅲ期NEC、手术干预治疗和脑室内出血≥3级的患儿比例高于晚发型组（P<0.05）。早发型组呼吸暂停、发热或体温不升的患儿比例高于晚发型组（P<0.05）。多因素logistic回归分析显示，喂养不耐受、血培养阳性的早发型败血症、重度贫血和有血流动力学意义的动脉导管未闭是极/超低出生体重早产儿早发型NEC发生的独立危险因素（P<0.05）。 结论 极/超低出生体重早产儿早发型NEC病情较晚发型NEC更严重；患有喂养不耐受、血培养阳性的早发型败血症、重度贫血或有血流动力学意义的动脉导管未闭患儿发生早发型NEC的风险较高。

Objective To investigate the clinical characteristics and risk factors for early-onset necrotizing enterocolitis (NEC) in preterm infants with very/extremely low birth weight (VLBW/ELBW). Methods A retrospective analysis was performed on the medical data of 194 VLBW/ELBW preterm infants with NEC who were admitted to Children's Hospital Affiliated to Zhengzhou University from January 2014 to December 2021. These infants were divided into early-onset group (onset in the first two weeks of life; n=62) and late-onset group (onset two weeks after birth; n=132) based on their onset time. The two groups were compared in terms of perinatal conditions, clinical characteristics, laboratory examination results, and clinical outcomes. Sixty-two non-NEC infants with similar gestational age and birth weight who were hospitalized at the same period as these NEC preterm infants were selected as the control group. The risk factors for the development of early-onset NEC were identified using multivariate logistic regression analysis. Results Compared with the late-onset group, the early-onset group had significantly higher proportions of infants with 1-minute Apgar score ≤3, stage III NEC, surgical intervention, grade ≥3 intraventricular hemorrhage, apnea, and fever or hypothermia (P<0.05). The multivariate logistic regression analysis showed that feeding intolerance, blood culture-positive early-onset sepsis, severe anemia, and hemodynamically significant patent ductus arteriosus were independent risk factors for the development of early-onset NEC in VLBW/ELBW preterm infants (P<0.05). Conclusions VLBW/ELBW preterm infants with early-onset NEC have more severe conditions compared with those with late-onset NEC. Neonates with feeding intolerance, blood culture-positive early-onset sepsis, severe anemia, or hemodynamically significant patent ductus arteriosus have a higher risk of early-onset NEC.