Peripartum depression is a common, serious complication in mothers. To assess the influence of infant care, sleep and growth on the risk of peripartum depression, 1,271 mothers of healthy one-month-old infants completed comprehensive questionnaires including the Edinburgh Postnatal Depression Scale. Relationships between high depression scores and variables related to infants' care, sleep and growth were assessed adjusting for other variables. High depression scores were found in 233 mothers, which were associated with variables related to infants' care (poor satisfaction with infant care support, p < 0.001; mothers' passive response to night-time fussing, p = 0.001), sleep (dim bedroom lighting, p < 0.05; short sleep duration, p < 0.05) and growth (poor weight gain, p < 0.05), as well as maternal variables (primiparas, p < 0.001; poor income satisfaction, p < 0.001; poor sleep satisfaction, p < 0.001; daytime sleepiness, p = 0.001). Considering the observed association between high depression scores and infants' care, sleep and growth, a multidisciplinary approach accounting for infant care would be required to prevent peripartum depression.