Gestational age was examined in the Norwegian data and no inverse trend with the length of gestation and later risk of gestational diabetes was found. However, those who were born early (< 34 weeks gestation), had a non-significantly greater risk for developing gestational diabetes.

When we looked at weight-for-gestational age, we observed an inverse trend that was similar to that observed for birth weight. Because absolute birth weight and weight-for-gestational age are highly related variables, the data were reanalyzed for births under 3,500g, and a similar inverse trend was found.

These findings suggest that intrauterine growth retardation and not prematurity is the important predictor for later risk for gestational diabetes.