Background: A number of studies have shown that maternal stress during pregnancy has effects on

offspring behaviour independent of postnatal measures of maternal stress. However, animal studies have

shown that behavioural development is influenced by the interaction of antenatal and postnatal

environments (Francis et al. 2003). Data are needed to test the co-action of antenatal and post-natal

environments in humans.

Aims: The proposed research has two aims: (1) to identify trajectories of familial risk from the prenatal to

the postnatal period, (2) to 'test whether familial risk trajectories up to age 8 years are associated with

child cognitive abilities and behaviour from 8 to 10 years. The design will provide evidence as to the

relative importance of antenatal versus postnatal environments and test additive versus interactive models

of antenatal and postnatal effects.

Hypothesis 1: We will identify trajectories that reflect (a) consistently low levels of familial risk, (b)

increasing risk from the antenatal to postnatal period, (c) decreasing risk from the antenatal to postnatal

period, (d) stable and high levels of familial risk.

Hypothesis 2a: If antenatal environments have enduring effects irrespective of postnatal environments,

children on the stable, high risk and declining trajectories will have poorer outcomes than children on the

stable, low risk and increasing risk trajectories.

Hypothesis 2b: If postnatal environments have effects on child outcome irrespective of antenatal

environments, then children on the stable, high risk and increasing risk trajectories will have poorer

outcomes than children on the stable, low risk and declining risk trajectories.

Hypothesis 2c: If antenatal and postnatal environments have additive effects, then children on the stable,

high risk trajectory will have the poorest outcomes, children on the stable, low risk trajectory will have

the most positive outcomes, and children on the increasing and declining trajectories will fall intermediate

to the other two groups.

Hypothesis 2d: If antenatal and postnatal environments have interactive effects, then children on the

stable, high risk trajectory will have poorer outcomes than the other three groups.

Analysis: The analysis would involve Cl) estimating trajectories of environmental risk from the antenatal

through the postnatal period up to age 8 years involving a composite index of financial hardship,

domestic violence (as reflected in mothers' reports of conflict with partner and in life events

questionnaire), child harm (as reflected in life events questionnaire), maternal social support, and

maternal depression and anxiety; (2) estimating associations between environmental risk trajectories and

child behaviour (symptoms of antisocial behaviour, depression, and attention deficit/hyperactivity) and

cognitive outcomes (IQ) at 8 to 10 years. Analyses would control for antenatal smoking and alcohol use

as well as parent education and parental history of antisocial behaviour and mental health problems.