Social capital and maternal mental health: Findings from secondary data analyses of two linked longitudinal trials in Australia

Problem: Low social capital has been identified as an important risk factor in the development of postpartum mental illness. Background: Evidence suggests that new and expectant mothers with higher levels of support have lower rates of maternal mental illness, yet few studies examine this relationship longitudinally. Aim: This study investigated the association between social capital in late pregnancy and maternal mental health up to 5 years postpartum. Methods: Secondary analysis of Communicating Healthy Beginnings Advice by Telephone trial data was conducted. Participants included women in late pregnancy recruited from seven Australian hospitals across New South Wales (n=1155). Outcomes were maternal stress at 6 months postpartum, and psychological distress at 3, 4, and 5 years postpartum. Data on demographics and maternal cognitive, structural, and total social capital were collected in late pregnancy. Multiple logistic regression was conducted at 6 months postpartum, and longitudinal analysis with multilevel mixed-effects logistic regression conducted from 3 to 5 years postpartum. Findings: Lower total social capital was associated with an increased likelihood of having higher stress at 6 months postpartum (AOR 1.61, 95 % CI 1.21-2.14). Lower total social capital was also associated with anxiety (AOR 1.44, 95 % CI 1.01-2.05) and higher levels of psychological distress (AOR 1.50, 95 % CI 1.15-1.95) at 3 to 5 years postpartum. Conclusions: Findings suggest that improving social capital in late pregnancy can mitigate postpartum mental health symptoms. Efforts to increase the social capital of new and expectant mothers should be made to prevent their mental illness postpartum.