OBJECTIVE This paper reports the findings of a prospective longitudinal study of 272 nulliparous pregnant women, which investigated as one of its objectives the psychological sequelae of obstetric procedures. METHOD Participants completed structured interviews and standardised, published psychometric questionnaires, including the Rosenberg Self-Esteem Scale and the Profile of Mood States late in pregnancy and again early in the postpartum period. RESULTS Little evidence was found to support the notion that the total number of obstetric interventions was linked to a deterioration in postpartum mood. Significant adverse psychological effects were associated with the mode of delivery. Those women who had spontaneous vaginal deliveries were most likely to experience a marked improvement in mood and an elevation in self-esteem across the late pregnancy to early postpartum interval. In contrast, women who had Caesarean deliveries were significantly more likely to experience a deterioration in mood and a diminution in self-esteem. The group who experienced instrumental intervention in vaginal deliveries fell midway between the other two groups, reporting neither an improvement nor a deterioration in mood and self-esteem. CONCLUSIONS The findings of this study suggest that operative intervention in first childbirth carries significant psychological risks rendering those who experience these procedures vulnerable to a grief reaction or to posttraumatic distress and depression.