Transient hyperammonemia in newborns: clinical and laboratory parameters and neurological outcomes in patients in the first year of life

BACKGROUND: Transient hyperammonemia in newborns (THAN) is a dangerous condition of the neonatal period that does not have a specific clinical picture, which often makes timely diagnosis difficult. Insufficient coverage of the problem of THAN in the literature, as well as the need to assess the neuropsychiatric development (NPD) of patients in the follow-up, served as the basis for this study. 
AIM: To evaluate clinical and laboratory manifestations of THAN and its influence on the neuropsychological development during the first year of life. 
MATERIALS AND METHODS: During the study, 22 preterm newborn patients were divided into 2 groups depending on the presence or absence of THAN: study group (n = 11) and comparison group (n = 11). All patients were assessed for risk factors, features of clinical manifestation of THAN, and neurological outcomes using the CAT/CLAMS scale at 3, 6, 9, and 12 months of age. 
RESULTS: Analysis of the obtained data showed that the depression syndrome was the leading one in the clinical picture of THAN (81.8%). Laboratory changes are characterized by the respiratory failure (p = 0.039), anemia (p = 0.023), hypoproteinemia (p = 0.049), hypoalbuminemia (p = 0.048), lower blood sodium levels (p = 0.019). In the constructed prognostic model for determining the probability of having THAN, the critical cutoff p level was 20% (p = 0.012). Assessment of the neuropsychiatric development showed that 41.6% of children who had THAN maintained a moderate neuropsychiatric development delay in the first year of life with predominant impairment of motor skill formation. 
CONCLUSIONS: Allocation of a risk group for THAN formation, timely prescription of a low-protein diet, correction of syndromic therapy, and monitoring of patients in the first year of life will help to avoid severe neurological disorders and reduce the need for rehabilitative measures.