Esketamine has rapid-onset antidepressant effects and may reduce the risk of postpartum depression in parturients with prenatal depressive symptoms. However, its adverse neuropsychiatric symptoms limits clinical application. Dexmedetomidine can alleviate these adverse symptoms and has independent antidepressant effect. This randomized, double-blind, placebo-controlled trial is designed to evaluate whether intranasal esketamine combined with dexmedetomidine can reduce the prevalence of postpartum depression in women with prenatal depressive symptoms.