Dr. Ginette Dionne and colleagues at Laval University in Quebec City studied 221 children of mothers who developed diabetes for the first time while pregnant and 2 612 control children of mothers who did not develop "gestational diabetes." All of the children had at least one measure of language documented between ages 18 months to seven years.
Results showed that infants of diabetic mothers scored markedly lower on most tests of "expressive" language.
Children of diabetic mothers were also twice as likely to be classified as having language impairment - defined as falling below the 15th percentile on at least two language measures.
Mom's level of education modulated the effects on language impairment, the researchers found, with children of mothers with no high school diploma more adversely affected by gestational diabetes. "Genetic modelling" studies also indicated that genes moderate the effect of gestational diabetes on expressive language.
Dionne's team speculates that "the more stimulating environments provided by educated mothers may diminish the initial impact of gestational diabetes on language outcomes," while at the same time warning that "the moderating effect of maternal education may simply reflect the moderating effect of genes."
They conclude that studies are needed to see if stimulation "through parental support or surrogate maternal care" might offset the effects of gestational diabetes on language development.