Neurodevelopment in 3-4 year old children exposed to maternal hyperglycemia or adiposity in utero (lay summary)

Krzeczkowski JE, Boylan K, Arbuckle TE, Dodds L, Muckle G, Fraser WD, Favotto LA, Van Lieshout  RJ, on behalf of The MIREC Study Group. Early Human Development. 2018 Oct;125:8-16. doi: 10.1016/j.earlhumdev.2018.08.005.

Pre-pregnancy obesity (adiposity) or maternal high blood glucose (hyperglycemia) have been linked to altered brain development in infants. A baby’s brain is rapidly developing both during pregnancy and in early life. Thus, maternal adiposity or hyperglycemia during pregnancy may impact the child’s cognition (IQ) and behavior. This study was designed to look at the associations between pre-pregnancy adiposity or hyperglycemia and child IQ and behavior at around 3 years of age.

Data from 808 mother-child pairs from the MIREC-CD Plus study were analysed. Pre-pregnancy adiposity was assessed by calculating the woman’s body mass index (BMI: weight in kg/height in m2). If the women had gestational diabetes or impaired glucose tolerance (measures of high blood glucose), they were considered to be hyperglycemic. The child’s IQ and behavior were assessed using various tests at around 3 years of age. Diet during pregnancy, the home environment, postpartum depression symptoms, maternal education and smoking in pregnancy were also considered as factors associated with child IQ and behavior.

Higher maternal BMI and excess blood glucose were both associated with lower IQ scores in children. Higher maternal BMI was also associated with child behavioral problems. However, when mother’s diet quality during pregnancy and the home environment were also considered, associations between adiposity, hyperglycemia and child IQ or behavior were no longer observed.

In conclusion, associations that have previously been observed between maternal adiposity or hyperglycemia and cognitive and behavioral problems in their children may be due to other factors. While it is well known that the home environment plays a major role in cognitive development of children, this study suggests that maternal diet quality during pregnancy may also be an important factor.