It is widely recognised that depression is common during the postpartum period and that maternal postnatal depression can have a detrimental effect on child development (the term ‘depression’ and ‘depressed’ is used as a short-hand for those women who scored above the specified cutoff on the Edinburgh Postnatal Depression Scale [EPDS]. The EPDS is not a diagnostic tool and the women had not been assessed formally, therefore they had not been diagnosed as clinically depressed).1–7 Investigations of the inter-relationships between maternal wellbeing and child development have mostly been conducted after childbirth with few studies collecting data prospectively, starting during pregnancy.8–10 There is increasing evidence that the mother’s mood during pregnancy is important. For example, uterine blood flow has been observed to change in association with anxiety during pregnancy,11–15 and antenatal anxiety in late pregnancy is independently associated with children’s behavioural/emotional problems at 4 years of age.16 The children of women in socio-economically deprived families, who are at risk of depression antenatally, are at greater risk of developmental delay at 2 years of age.17 The strongest predictor of postnatal depression is depression in pregnancy; however, antenatal depression may be more common than postnatal depression.18,19 Although severity and chronicity of maternal depression are related to increased developmental problems in their children,20–22 less is known about the importance of timing of the exposure to maternal depression, in particular whether pregnancy is a sensitive period.
Closing the gap in the evidence about associations between parental depression and child health outcomes has important implications for both families and healthcare practitioners. The aim of this study was to assess the association between maternal depression in pregnancy and child development. Although fathers’ mood influences child development,23 the focus of this paper is on depressive symptoms in mothers. We hypothesised that antenatal depression scores have an impact on early childhood development that is independent of postnatal depression. This was tested, first, by investigating the association between maternal antenatal depression and a measure of child development and second, by examining the independent effects of antenatal depression. Data used to test this hypothesis were derived from the Avon Longitudinal Study of Parents and Children (ALSPAC),24 a large community sample in England that has been followed prospectively since early pregnancy.