My husband and two children all have type 1 diabetes. If we decided to have more children, Is there any test to predict if that child would develop diabetes?

At the present there is no such test. The overall chance of a third child having type 1A (autoimmune) diabetes is still about 1:20 in Caucasian families, and it may be just statistical happenstance that your husband and two children are already affected. At the same time, one can’t help wondering if the population average has not been biased in your case by some genetic factor or especial exposure to one of the as yet unknown environmental triggers of actual clinical diabetes. In a few years, it might be possible to make a much more accurate prediction on the basis of amniocentesis of fetal cells, but at present, the only way to refine the general figure would be for you and your husband both to be HLA (Human Leukocyte Antigen) typed to find out whether you both were homozygous for high risk genes, had a protective gene or were somewhere in between.

DOB