1 Neuroscience Graduate Program, McMaster University, Hamilton, Ontario, Canada.
2 Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Ontario, Canada.
3 Department of Psychology, Concordia University, Montreal, Quebec, Canada.
4 Department of Family Relations & Applied Nutrition, University of Guelph, Guelph, Ontario, Canada.

Background: Optimal maternal nutrition during pregnancy has been linked to better cognitive and behavioral development in children. However, its influence on the effects of suboptimal postnatal exposures like reduced stimulation and support in the home is not known.

Objectives: To examine the effect of maternal pregnancy diet on executive function and/or behavioral development in children raised in suboptimal home environments.

Methods: Data were provided by 808 mother-infant dyads from the Canadian Maternal-Infant Research on Environmental Chemicals-Child Development study. Maternal pregnancy diet was self-reported using the Healthy Eating Index 2010 questionnaire. Stimulation and support in the home was assessed using the Home Observation for Measurement of the Environment (HOME) when children were 3-4 y old. Child executive function was reported by mothers at this age using the Behavior Rating Inventory of Executive Functioning-Preschool Edition, and child behavior was assessed using the Behavior Assessment System for Children-2nd Edition. We examined the interaction of maternal pregnancy diet and postnatal HOME scores on child executive function and behavior using linear regression adjusted for maternal education, postpartum depression, prepregnancy BMI, and smoking.

Results: Maternal pregnancy diet was associated with an increasingly positive association with child working memory (ß: 0.21; 95% CI: 0.82, 3.41; P = 0.001), planning (ß: 0.17; 95% CI: 0.38, 2.84; P = 0.007), and adaptability (ß: -0.13; 95% CI: -1.72, -0.08; P = 0.032) as levels of postnatal stimulation decreased.

Conclusions: The positive association of maternal pregnancy diet quality and executive function and adaptability in 3- to 4-y-olds appeared to increase with decreasing levels of postnatal stimulation and support. These results suggest that overall maternal pregnancy diet could be linked to better child neurodevelopment in families experiencing barriers to providing stimulation and support to children in their home.