More than half the women with a history of psychosis have a psychiatric episode in the first year after childbirth.

MAIN RESULTS Prognosis: Women with a history of psychosis are at high risk of a psychiatric episode in the first year after childbirth (see table). Psychosis as a risk factor for post-natal depression: Women with a history of psychosis are more likely to have postnatal depression compared with age matched controls in the first year after childbirth (RR adjusted for active illness 2.04, 95% CI 1.45 to 2.88). CONCLUSIONS Women with a history of psychosis are at high risk of a psychiatric episode in the first year, and are more likely to have postnatal depression compared with women without a history of psychosis. In women with a history of psychosis, preventive psychiatric services may be warranted for at least a year after childbirth.