Maternal gestational diabetes mellitus (GDM) has been linked to high body mass index among offspring, even when they become adults.
Women with this type of diabetes tend to give birth to heavier babies but research carried out in Sweden has shown that this weight disparity continues into adulthood.
Scientists based at the University of Bristol carried out a prospective cohort study of 280,866 Swedish men.
Of these, 1,475 of the men had been exposed to GDM in the womb. Members of this category had a BMI 0.94kg/m2 greater than their brothers who were born before the mother had the condition.
Similar BMI increases were noted in men who did not have siblings.
The study authors wrote: "The strong association of maternal pregnancy diabetes mellitus with offspring BMI that we have found within siblings and between non-siblings in the entire population highlights the importance of identifying and appropriately treating pregnancy diabetes mellitus, not only for immediate perinatal reasons, but also for the long-term health of the offspring.
"These findings support long-term funding of randomised, controlled trials of pregnancy diabetes treatment to determine the effect of such treatments on the long-term risk of greater adiposity and associated consequences in offspring," they conclude.
The research findings appear in the journal Circulation.