• antenatal depression;
  • child development;
  • pregnancy;
  • postnatal depression

Objective  Postpartum depression in mothers is associated with developmental problems in their children. Many women who are depressed following childbirth are also depressed during pregnancy. The aim of this study was to examine the associations between maternal depressive symptoms during pregnancy and child development at 18 months of age.

Design  A prospective cohort study, Avon Longitudinal Study of Parents and Children.

Setting  The former county of Avon, southwest England.

Population  All pregnant women in the defined area with delivery dates between April 1991 and December 1992, 9244 women and their children.

Methods  Data were collected antenatally, at 18 and 32 weeks of gestation and at 8 weeks and 8 months postnatally, through postal questionnaires, including a self-report measure of depression (Edinburgh Postnatal Depression Scale [EPDS]). By the time their child was 18 months old, women completed five further questionnaires about their children’s health and development.

Main outcome measure  Child development at 18 months using a modified Denver Developmental Screening Test (modified DDST).

Results  Applying the standard 12/13 cutoff, 1565 (14%) women were depressed antenatally but not at either time-points postnatally. Employing the modified DDST, 893 (9%) children were developmentally delayed at 18 months of age. Persistent depression (EPDS ≥ 10 at both time-points) is associated with developmental delay (adjusted OR 1.34, 95% CI 1.11–1.62). Applying the 12/13 and 14/15 cutoffs gave similar results. After further adjustment for postnatal depression, the effect sizes were slightly attenuated.

Conclusions  These findings highlight the importance of depression in pregnancy. Some effects on child development attributed to postpartum depression are caused in part by depressive symptoms during pregnancy.