Impact of maternal depression on infant nutritional status and illness: a cohort study.

BACKGROUND The risk for emotional and behavioral problems is known to be high among children of depressed mothers, but little is known about the impact of prenatal and postnatal depression on the physical health of infants. OBJECTIVE To determine whether maternal depression is a risk factor for malnutrition and illness in infants living in a low-income country. DESIGN Prospective cohort study. SETTING Rural community in Rawalpindi, Pakistan. PARTICIPANTS Six hundred thirty-two physically healthy women were assessed in their third trimester of pregnancy to obtain at birth a cohort of 160 infants of depressed mothers and 160 infants of psychologically well mothers. MAIN OUTCOME MEASURES All infants were weighed and measured at birth and at 2, 6, and 12 months of age, and they were monitored for episodes of diarrhea and acute respiratory infections. The mothers' mental states were reassessed at 2, 6, and 12 months. Data were collected on potential confounders of infant outcomes, such as birth weight and socioeconomic status. RESULTS Infants of prenatally depressed mothers showed significantly more growth retardation than controls at all time points. The relative risks for being underweight (weight-for-age z score of less than -2) were 4.0 (95% confidence interval [CI], 2.1 to 7.7) at 6 months of age and 2.6 (95% CI, 1.7 to 4.1) at 12 months of age, and the relative risks for stunting (length-for-age z score of less than -2) were 4.4 (95% CI, 1.7 to 11.4) at 6 months of age and 2.5 (95% CI, 1.6 to 4.0) at 12 months of age. The relative risk for 5 or more diarrheal episodes per year was 2.4 (95% CI, 1.7 to 3.3). Chronic depression carried a greater risk for poor outcome than episodic depression. The associations remained significant after adjustment for confounders by multivariate analyses. CONCLUSIONS Maternal depression in the prenatal and postnatal periods predicts poorer growth and higher risk of diarrhea in a community sample of infants. As depression can be identified relatively easily, it could be an important marker for a high-risk infant group. Early treatment of prenatal and postnatal depression could benefit not only the mother's mental health but also the infant's physical health and development.