目的 通过回顾性多中心现状调查，了解新生儿高氨血症的发病率、病因分类、临床特征及预后情况。方法 以2017年1月—2022年11月28家参与单位分娩并入住新生儿科治疗的血氨>100 μmol/L的新生儿作为研究对象，用描述性研究方法对确诊高氨血症新生儿的发病率、病因分类、临床特征、基因表型及预后随访等情况进行分析总结。结果 观察期间28家单位总分娩量708 421例，73例符合新生儿高氨血症诊断标准，其中男44例、女29例。病因分类中先天遗传性高氨血症32.88%（24例），暂时性高氨血症15.07%（11例），继发性高氨血症16.44%（12例），另有26例原因不明（35.61%）。主要临床表现有反应差、气促、喂养困难、抽搐、意识障碍等。主要异常实验室检查为代谢性酸中毒、血乳酸增高、低血糖、电解质紊乱，血氨基酸和/或尿氨基酸异常，13例进行了基因检查的患儿中11例发现异常。治疗上除常规对症支持治疗外，主要采用了精氨酸排氨（21例）、补充肉碱（8例）、血液净化（9例）以及腹膜透析（3例）。预后方面，24例先天遗传性高氨血症患儿死亡10例，放弃治疗6例，好转出院8例；12例继发性高氨血症患儿死亡1例，放弃治疗3例，预后不详1例，治愈出院7例；11例暂时性高氨血症患儿均治愈或好转出院；而26例不明原因高氨血症病例死亡17例，放弃治疗4例，预后不详3例，好转出院2例。结论 新生儿高氨血症发病率不高，但病情进展快，病死率高，尤其是先天性遗传高氨血症和不明原因高氨血症病例。提高临床医师对该病的认识，尽量做到早诊断，早治疗，可减少死亡及严重并发症。加强产前咨询，建立新生儿高氨血症筛查体系和新生儿高氨血症注册登记系统，具有积极的临床意义。

Objective To investigate the incidence, etiological classification, clinical features and prognosis of neonatal hyperammonemia through a retrospective multi-center status survey. Methods Neonatal patients with blood ammonia levels more than 100 μmol/L who were treated in 28 participating units between January 2017 and November 2022 made up the study population. The incidence, etiological classification, clinical traits, genetic phenotype, and prognostic follow-up of neonates with confirmed hyperammonemia were analyzed using descriptive study methodologies. Results During the observation period, the total number of deliveries in 28 units was 708421, and 73 newborns met the diagnostic criteria of neonatal hyperammonemia, including 44 boys and 29 girls. The etiological classification included congenital hyperammonemia (24 cases, 32.88%), transient hyperammonemia (11 cases, 15.07%), secondary hyperammonemia (12 cases, 16.44%), and unexplained hyperammonemia (26 cases, 35.61%). The main clinical manifestations were poor response, shortness of breath, feeding difficulties, convulsions and impaired consciousness. The main abnormal laboratory tests were metabolic acidosis, increased blood lactate, hypoglycemia, electrolyte disorders, abnormal blood and/or urine amino acids. Genetic tests were performed in 13 patients, and abnormalities were found in 11 of them. In addition to conventional symptomatic supportive treatment, arginine intravenous drip (21 cases), carnitine supplementation (8 cases), blood purification (9 cases) and peritoneal dialysis (3 cases) were mainly used. The prognosis for the 24 cases of congenital hereditary hyperammonemia was 10 deaths, 6 treatment discontinuations, and 8 discharges. Among the 12 children with secondary hyperammonemia, 1 died, 3 gave up treatment, 1 had an unknown prognosis, and 7 were cured and discharged from hospital. All 11 cases of temporary hyperammonemia were cured or improved and discharged from hospital. Among 26 cases of unknown hyperammonemia, 17 died, 4 gave up treatment, 3 had unknown prognosis, and 2 were discharged from hospital after improvement. Conclusions Neonatal hyperammonemia is uncommon, but it progresses swiftly and has a high risk of mortality, particularly in cases of congenital genetic hyperammonemia and unexplained hyperammonemia. Raising doctors' awareness of the condition and promoting early detection and treatment can reduce mortality and serious consequences. Moreover, setting up screening and registration procedures for newborn hyperammonemia as well as improving prenatal consultation are helpful for clinical outcomes.