Objective To analyze the relationships of expressions of serum microRNA (miR)-20a-5p and miR-128-3p with cranial nerve development in the premature infants with hypoxic-ischemic encephalopathy (HIE).

Methods A total of 95 HIE premature infants were selected as HIE group, and according to the severity of HIE, they were divided into mild group (n=27), moderate group (n=46) and severe group (n=22); another 95 premature infants without HIE in the same period were selected as control group. Apgar score and the Neonatal Behavioral Neurological Assessment (NBNA) score were performed in both groups; the expression levels of miR-20a-5p and miR-128-3p in serum were detected by real-time fluorescence quantitative polymerase chain reaction (qRT-PCR); Spearman method was used to analyze the correlations of serum miR-20a-5p and miR-128-3p levels with Apgar score and NBNA score; the values of serum miR-20a-5p and miR-128-3p levels in diagnosing HIE in premature infants were analyzed by receiver operating characteristic (ROC) curve.

Results Compared with the control group, the levels of serum miR-20a-5p and miR-128-3p in the HIE group increased significantly, while the Apgar score and NBNA score decreased significantly (P < 0.05). In the mild, moderate, and severe groups, the levels of serum miR-20a-5p and miR-128-3p increased gradually, while the Apgar score and NBNA score decreased gradually, with the significant between-group differences (P < 0.05). Spearman analysis results showed that the level of serum miR-20a-5p was negatively correlated with the Apgar score and NBNA score (r=-0.659, -0.548, P < 0.001), and the level of serum miR-128-3p was negatively correlated with the Apgar score and NBNA score (r=-0.582, -0.499, P < 0.001). The combined prediction of serum miR-20a-5p and miR-128-3p for HIE in premature infants had an area under the curve (AUC) of 0.920, with a sensitivity of 78.95% and a specificity of 97.89%. The predictive efficacy of the combined model was superior to that of miR-20a-5p and miR-128-3p alone (P < 0.05).

Conclusion The serum levels of miR-20a-5p and miR-128-3p increase in the premature infants with HIE, and are closely related to the severity of the disease and the development of brain nerves. The combined detection of miR-20a-5p and miR-128-3p has good predictive value for the occurrence of HIE in premature infants.