98. Relationships between maternal body mass index and child cognitive outcomes at 3 years of age are buffered by specific early environments in a prospective Canadian birth cohort (lay summary)

West Z, Demchenko I, Clark L, White M, MacFarlane AJ, Fraser WD, Arbuckle TE, 

A number of maternal factors such as general health, nutrition, education and the home environment can shape development of the fetus and child.  The objective of this study was to examine whether maternal underweight, overweight or obesity prior to pregnancy was linked to poorer cognitive outcomes in early childhood.  In addition, the researchers studied whether other factors including  breastfeeding practices, maternal education and the home environment might modify this association.

MIREC moms reported their height and weight prior to the pregnancy, which was used to calculate their Body Mass Index (BMI) (categorized as underweight, normal weight, overweight or obese).  At approximately 3 years of age, the MIREC children’s cognitive ability (measured by IQ scores) was determined and their home environment evaluated.

Amongst the 528 mother-child pairs, the researchers from Carleton University found that increasing maternal pre-pregnancy BMI was associated with lower scores for child IQ.  However, BMI was less associated with a lower child IQ if the woman had a higher education level or a higher quality home environment.

In conclusion, higher maternal education level and higher quality home environment buffered the negative association observed between higher maternal pre-pregnancy BMI and child IQ scores.

These findings underscore that multiple factors can influence child cognition in early life, some adversely and others that can buffer against negative effects and support resiliency.