AIMS: The first year after childbirth involves a major transition for women, which can accentuate inadequacies and feelings of powerlessness, making them vulnerable to depression. The aim of this study was to investigate the prevalence and frequency of maternal postpartum depressive symptoms at different times after giving birth (0-21 months).

METHODS: Data were collected cross-sectionally using a web questionnaire containing the Edinburgh Postnatal Depression Scale (EPDS). A total of 888 mothers with children in the age range 0-21 months responded.

RESULTS: The results showed different levels of depression over the range of months included in the study. The overall prevalence using EPDS ⩾ 12 was 27.8%. There were higher levels at 9-12 months and 17-21 months. The highest levels of symptoms of depression were found at nine, 12, and 17 months after birth, and the lowest levels at two and 16 months.

CONCLUSIONS: Many mothers experience symptoms of depression after giving birth that can continue well beyond the child's first year. We have identified different levels of depression at different points in time after giving birth, with highs and lows throughout the first 21 months. This highlights a need to screen for depression more than once during the first years, as well as a closer cooperation between midwives and child healthcare nurses in supporting mothers in the transition to motherhood. This is an important aspect of public health, which not only involves mothers with symptoms of depression, but also their ability to care for their child and a possible negative impact on the child's development.