Maternal psychological distress and child weight at 24 months: investigating indirect effects through breastfeeding in the All Our Families cohort.

objectiveMaternal psychological distress in pregnancy has been associated with both breastfeeding duration and child weight at 24 months; however, the potential that breastfeeding duration partially mediates the risk of maternal mental health problems during pregnancy on child weight classification has not been examined. The current study investigated this proposed relationship.

methodsData was taken from the All Our Families (AOF) cohort, an ongoing prospective pregnancy cohort located in Calgary, Canada. Psychological distress, defined as clinically significant symptoms of anxiety and depression, was assessed via self-report and measured between 34 and 36 weeks of gestation. Breastfeeding duration was assessed in the postpartum by self-report. Child overweight classification was defined as a weight-for-length/height z-score at or above the 97th percentile as per World Health Organization's child growth guidelines.

resultsIn this sample of 1582 mother-child pairs, there was no direct relationship between psychological distress and child overweight status. Both anxiety (B = - 5.40, p = 0.001) and depression (B = - 6.54, p = 0.008) were associated with decreased weeks breastfeeding. Breastfeeding duration mediated the association between maternal prenatal psychological distress and child overweight status at 24 months, for both anxiety (B(SE) = 0.10(0.05), CI 0.03-0.21) and depression (B(SE) = 0.11(0.07), CI 0.01-0.27). Covariates included maternal age, education, ethnicity, income, pre-pregnancy BMI, gestational weight gain, and infant birth weight.

conclusionsThe results of this longitudinal cohort analysis support an indirect relationship between maternal psychological distress in pregnancy and the childhood overweight/obesity at 24 months old, mediated through breastfeeding duration.