To investigate the relationship between premenstrual mood changes and maternal mental health in the perinatal period, a prospective questionnaire survey of 1,329 women was carried out. Women with a premenstrual mood changes (irritability) before pregnancy showed significantly higher Zung's Self-rating Depression Scale (SDS) scores than those without it, throughout pregnancy and the postpartum period (6 time points: early, middle, and late pregnancy, 5 days, 1 month, and 6 months after childbirth). In addition, women with premenstrual irritability had greater anxiety about pregnancy and delivery, were more reluctant to accept mother roles, and felt their babies (fetuses or neonates) were more vulnerable. These findings suggest that premenstrual mood change is correlated with unstable mental health throughout the perinatal period.