Influence of maternal age at delivery and birth order on risk of type 1 diabetes in childhood: prospective population based family study
Children of older mothers have an increased risk of diabetes according a new study published in this week's BMJ. The risk is highest among first born children of mothers who start their families late.
Professor Edwin Gale and colleagues at Southmead Hospital in Bristol looked at 1375 families in the Oxford area in which one or more child had diabetes. They found that the mother's age at delivery was strongly related to risk of type 1 (insulin dependent) diabetes. The risk increased by 25% for each five year band of maternal age, so that a 45 year old mother was more than three times likely to have a child who developed diabetes than a 20 year old mother. To a lesser extent the risk of diabetes was also linked to older fathers.
Risk of type 1 diabetes was highest among first born children of older parents. Second children and their younger brothers or sisters were progressively less at risk of developing the condition.
Throughout the country women are in general having their children at an older age: between 1970 and 1996 the proportion of children born to mothers aged 30-34 years increased from 15% to 28%. The authors of the BMJ paper say: "The increase in maternal age at delivery in the UK over the past two decades could partly account for the increase in incidence of childhood diabetes over this period."
Contact:
Dr Polly Bingley, Diabetes & Metabolism, Div of Medicine, University of Bristol Southmead Hospital, UK Email: polly.bingley@bristol.ac.uk