A woman's diet during pregnancy can cause changes to her unborn child's DNA that may significantly increase its risk of obesity and make it more likely to developing type 2 diabetes during its lifetime, according to new research from the University of Southampton.heir mothers were also surveyed about their diet during pregnancy. The results showed that women who ate a poor diet while pregnant were more likely to have children with a greater degree of epigenetic changes, DNA alterations that affect the function of certain genes.