Most of the previously established risk factors [1
] played a role in predicting antenatal depression, postnatal depression and parenting stress.
An impressive 78% of the variance of antenatal depression was explained by seven factors: low self-esteem, antenatal anxiety, low social support, negative cognitive style, major life events, low income and a history of abuse. Age, education and depression history were not significant in the regression but were significantly correlated with antenatal depression.
Antenatal depression, history of depression and concurrent parenting stress accounted for 66% of the variance in explaining postnatal depression. Furthermore, antenatal depression was revealed as a dominant mediator between seven risk factors and postnatal depression, namely antenatal anxiety, major life events, low self-esteem, low social support, negative cognitive style, history of abuse and low income. Age was not found to be significant in the regression but was correlated with postnatal depression. Education was not significantly related to postnatal depression.
The only identified factor for parenting stress was concurrent postnatal depression, which alone accounted for 45% of the variance. None of the antenatal risk factors were directly predictive of parenting stress. However, postnatal depression was revealed as a dominant mediator between five risk factors and parenting stress: antenatal anxiety, low self-esteem, low social support, negative cognitive style and history of depression. While antenatal depression did not contribute to the prediction of parenting stress, even through the mediation of postnatal depression, antenatal depression was found to be significantly related to parenting stress. Age, education, income, history of abuse and major life events were not significantly related to parenting stress.
Limitations of this study include the under-representation of women who are not partnered or from diverse cultures in the sample and subsample, which largely comprised married, Australian-born women. Compared with Victorian averages from 2004 [55
] this sample comprised a higher percentage of partnered (95.9% this sample; 86.5% Victorian average) and Australian-born women (87.5% this sample; 76.1% Victorian average). Thus, the results of this study may have limited generalisability to women from other cultures or unpartnered women. Those categorised in the antenatal depressed group were assumed to have their depressive onset in pregnancy but this was not established. As such, some women identified as depressed antenatally may have been depressed prior to conception. Previous research found that time of depressive onset, prior to or during pregnancy, was related to the duration of the depressive episode [7
]. Multiple risk factors for antenatal depression were measured concurrently in the antenatal period raising two conceptual limitations. First, pervasive negative reporting may have occurred with numerous concurrent measures being completed by those currently depressed. Second, the interpretation of significant risk factors as truly predictive of antenatal depression is limited given the risk factors were measured concurrently rather than prospectively. Similarly, postnatal depression and parenting stress were measured concurrently raising limitations about a genuine predictive relationship. The overlap between the constructs of postnatal depression and the PSI, as previously acknowledged, further limits the ability to interpret results. However, an attempt was made to minimise the confounding of results by confirming that observed differences on the PSI between depressed and non-depressed group were not solely due to the depression subscale. Finally, although this study assessed many risk factors, it is a challenge to account for all previously identified variables in any one multivariate study. Caregiving history including a harsh, rejecting parenting style in one's family of origin and attachment styles have been linked with antenatal and/or postnatal depression [56
] and were not accounted for in this study.
These limitations provide future research directions. Most notably, onset of depression, prior to or during pregnancy, may relate to duration of the depressive episode. Additionally, research into effective interventions for antenatal depression in an effort to diminish or ameliorate postnatal depression and early parenting stress seem warranted.
Integrative model of risk factors for antenatal depression, postnatal depression and parenting stress
In previous work, we conceptualised a biopsychosocial model of postnatal depression, which comprised vulnerability factors, precipitating factors, maintaining factors and considered there may be some mediating factors in the presentation of postnatal depression [29
]. Here, we propose a broader contextual model of adjustment in pregnancy, birth and motherhood. We highlight the importance of antenatal stressors, personal resources and predisposing factors in the development and maintenance of antenatal depression and subsequent postnatal depression and parenting stress (Figure ). The three outcome measures are embedded within the context. This model is an overall schematic representation of the results from this study and was not specifically tested. It does not take into account the relative weighting of each risk factor variable in relation to the three outcome measures.
A psychosocial model of antenatal depression, postnatal depression and parenting stress.
The strongest predictor of postnatal depression was antenatal depression, which also served as a mediator between many risk factors. Similarly, postnatal depression was the strongest predictor of parenting stress and postnatal depression also served as a mediator between many risk factors. These relationships are depicted by the suggested linear progression from the multiple risk factors to antenatal depression, which is then predictive of postnatal depression, which in turn predicts parenting stress. The relationship between the three outcome measures is important in creating an integrative risk profile, as seen in Figure .