Examining maternal depression, birthweight and linear growth: Findings from the South African National Income Dynamics Study

Background. Literature is inconclusive regarding an association between maternal depression, low birthweight (LBW) and stunting in early childhood. While some studies have found an association, others have not. Maternal food insecurity is a risk factor for both maternal depression and reduced linear growth in early childhood.  Objective. This study examined the relationship between maternal depression, food insecurity, LBW and stunting in the first five years of life. The study employed longitudinal data of South African women and children from the National Income Dynamics Study (NIDS).  Methods. Mothers were classified into four groups: food insecure and depressed; food insecure only; depressed only; and neither food insecure nor depressed. During data collection, 22% of women were pregnant and the remaining 78% were pre-conception. The primary outcomes were low birthweight and height-for-age (HAZ) scores. Generalised Linear Mixed Effects (GLME) models were used to account for women having more than one child. GLME models with a Gaussian link function were used to compare mean differences in birthweight and HAZ scores. Multivariable regression models were used to examine factors associated with depression.  Results. Food insecurity was significantly associated with depression among pre-conceptional and pregnant women. There was no statistically significant difference in birthweight or linear growth across groups, but this may be influenced by proximity of depression measurement in relation to outcomes.  Conclusion. Food insecurity is a potentially modifiable risk factor for depression and may be a confounding factor in studies that have found associations between depression and child health outcomes.