A genetic link between low birth weight and adulthood diabetes has been firmly established by researchers.
A team of scientists located two genetic regions that influence birth weight, with one also connected with type 2 diabetes.
The research involved experts from the UK and was based on 19 European studies of birth and pregnancy.
It was the first time a concrete association had been made despite scientists knowing for some time that small babies were increasingly likely to develop the disease.
They also knew that a mother's diet and nutrition affected her child's weight and future risk of disease in a process known as "programming".
The research was published in Nature Genetics and revealed that one variant in a gene called ADCY5 was linked to both birth weight and type 2 diabetes.
People who inherit two risk copies of this variant are 25% more likely to get diabetes in adulthood than those who inherit two non-risk copies, while also weighing less at birth.
The paper said: "This is robust evidence that the widely described association between lower birth weight and subsequent type 2 diabetes has a genetic component, distinct from the proposed role of programming by maternal nutrition.
"Further understanding of these associations will illuminate the biological pathways important for foetal growth and its relationship with adult diseases."