Check out this page. The author is my cousin, Sarah Howard. She is herself a diabetic and a mother, and she initiated her research after her not-quite-2-year-old son was diagnosed with Type 1 diabetes also. She's searched high and low for possible causes of the disease in very young children, and she's pulled together a whole lot of hypotheses about what might be increasing the numbers of children diagnosed with Type 1 and Type 2 diabetes.
What caught my eye is the following related to gestation and birth:
"Interestingly, an analysis of data from 20 studies found that Caesarean sections were associated with a 20% increased risk of type 1 diabetes in offspring."
Yet another reason to ditch the C-section and go natural if you can. She also puts in a plug for breastfeeding as a way to reduce the risk of type 1 diabetes in children.