Abstract： Objective To evaluate the impact of anxiety and depression in mothers on newborn birth weight and explore the correlation between late pregnancy salivary cortisol levels and newborn birth weight.Methods Pregnant women with singleton pregnancies who attended the obstetrics outpatient department of the Shenzhen Guangming District People's Hospital from January to December,2021 were assessed for anxiety and depression.Forty pregnant women with anxiety and depression were selected as the case group,and 50 normal pregnant women who attended during the same peri-od were selected as the control group.Salivary cortisol levels and sleep emotion assessments were performed in the late pregnancy period.The salivary cortisol levels and delivery outcomes were compared between the two groups,and the corre-lation between salivary cortisol levels and newborn birth weight was analyzed.Results The salivary cortisol levels of preg-nant women with depression and anxiety in the case group were significantly higher than those in the control group(P＜0.001).There was no significant difference in gestational age and birth weight between the two groups(P＞0.05),but the rate of cesarean section in the case group was significantly higher than that in the control group(57.5％vs.24.0％).Salivary cortisol levels in late pregnancy were negatively correlated with birth weight,but the correlation was not significant(P＞0.05).Conclusion Pregnant women with anxiety and depression have elevated levels of salivary cortisol in late pregnancy and a higher rate of cesarean section.No correlation was found between salivary cortisol levels and newborn birth weight.