Babies born to mothers who were obese during pregnancy are three times more likely to develop type 2 diabetes in later life, research by the University of Edinburgh suggests.
The proportion of obese mothers has increased five-fold from around one in 30 during the 1950s to almost one in six between 2000 and 2011.
Researchers say public health interventions are urgently needed to help women planning pregnancies to maintain a healthy weight.
Being overweight, but not obese, during pregnancy increases risk of diabetes in the child by almost half.
The findings add to the list of health problems linked to offspring of obese pregnant women, which also include heart disease, behavioural problems and early death.
The team studied birth records from more than 100,000 people born between 1950 and 2011 in the Aberdeen area and linked them with the national register for diagnosed diabetes in Scotland.
Figures revealed around one quarter of women were overweight during pregnancy over the 60-year period. One in ten were obese, with a body mass index (BMI) greater than 40.
Children from women overweight or obese during pregnancy were more likely to develop either type of diabetes in their lifetime – type 1 or type 2 . Risks were higher for type 2 diabetes.
Around half of all women of childbearing age are overweight or obese in the UK.
The study, published in the journal Diabetologia, was funded by Tommy’s, the baby charity, and the UK Medical Research Council.
Professor Rebecca Reynolds, of the university’s Tommy’s centre for maternal and fetal health, said: “We found an increased risk of developing diabetes in children born to obese mothers, not linked to sociodemographic factors.
“Our findings underline the urgent need to find ways of helping plan for pregnancy by optimising health, including reaching and maintaining a healthy weight.”
A Scottish Government spokesman said: “We are currently working on an action plan with NHS Health Scotland which will broaden the information and support available to all women of child bearing age across Scotland, as well as their families.
“This is in addition to our Diet and Healthy Weight Delivery Plan, published in 2018, setting out our ambition to halve childhood obesity by 2030, which includes an additional £42m investment in weight management services, with interventions to support women with, or at risk of, gestational diabetes.”