To investigate the correlation between the abnormal blood glucose levels at different time points in oral glucose tolerance test (OGTT) of pregnant women with gestational diabetes mellitus (GDM) and their neonatal brain injury. Methods: A total of 76 pregnant women with GDM who gave birth in the hospital from February 2022 to September 2022 were included the study group and 50 healthy pregnant women who gave birth in the same hospital during the same period were selected in control group. The neonatal behavior neurological assessment (NBNA) was applied to determine the presence or absence of neonatal brain injury in the two groups. The NBNA scores and the incidence of neonatal brain injury were compared between the groups. According to the abnormality count of OGTT results of the women in the study group at different time points, the women were divided in different groups, and the NBNA scores and the incidence of neonatal brain injury were analyzed and were compared among these groups. The correlation between the abnormal blood glucose levels at different time points of the women in the study group and their neonatal brain injury was analyzed. Results: The total NBNA score (35.5±1.3 points) of the women in the study group was significantly lower than that (36.5±1.5 points) of the women in the control group, and the incidence of the neonatal brain injury (17.1%) in the study group was significantly higher than that (4.0%) in the control group (all P＜0.05). The abnormal blood glucose rates of the neonates of the women with GDM before, and 1h and 2h after taking sugar in OGTT were 77.6%, 55.3%, and 38.2%, respectively. The percentages of the abnormal blood glucose level of the women in the study group at 1, 2 and 3 time points of OGTT were 48.7%, 31.6%, and 19.7%, respectively. With the increased number of the time points of the abnormal blood glucose level of the women, the NBNA score of their newborn had decreased gradually (P＜0.05). The incidence of the neonatal brain injury (2.7%) of the women with abnormal blood glucose level in 1 time point was significantly lower than that (24.8%) of the women with abnormal blood glucose level in 3 time points (P＜0.05). There were significant differences in the neonatal NBNA scores, including general condition, the passive muscle tone, the behavioral ability, and other, and the incidence of neonatal brain injury between the women with normal blood glucose level and the women with abnormal blood glucose level in 1h of OGTT in the study group (P＜0.05). Multiple linear regression analysis showed that the abnormal blood glucose level of the women in 1h of OGTT was positively correlated with their neonatal general condition, passive muscle tension, and behavioral ability score (P＜0.05). Conclusion: The abnormal blood glucose levels at different time points in OGTT of the pregnant women with GDM are correlated with their neonatal brain injury. Timely diagnosis and intervention should be conducted in the women with GDM according to their abnormal blood glucose level at each time point in OGTT, so as to avoid their neonatal brain injury as far as possible.