In low- and middle-income countries little is known about changes in women's mental health status from the perinatal period to 15 months postpartum or the factors associated with different trajectories.

To determine the incidence and rates of recovery from common mental disorders (CMD) among rural Vietnamese women and the risk and protective factors associated with these outcomes from the perinatal period to 15 months after giving birth.

In a population-based prospective study, a systematically recruited cohort of women completed baseline assessments in either the last trimester of pregnancy or 4–6 weeks after giving birth and were followed up 15 months later. The common mental disorders of major depression, generalised anxiety and panic disorder were assessed by psychiatrist-administered Structured Clinical Interview for DSM-IV Disorders at both baseline and follow-up.

A total of 211 women provided complete data in this study. The incidence rate of CMD in the first postpartum year was 13% (95% CI 8–19), and 70% (95% CI 59–80) of women who had perinatal CMD recovered within the first postpartum year. Incidence was associated with having experienced childhood maltreatment, experiencing the intimate partner as providing little care, sensitivity, kindness or affection, and the chronic stress of household poverty. Recovery was associated with higher quality of a woman's relationships with her intimate partner and her own mother, longer period of mandated rest following birth, and sharing of domestic tasks and infant care.

Modifiable social factors, in particular the quality of a woman's closest relationships with her partner and her own mother, and participation by family members in domestic work and infant care, are closely related to women's mental health in the first year after giving birth in resource-constrained settings.