Here is an interesting article.
http://www.time.com/time/health/arti...656786,00.html
A little snippet
Researchers analyzed medical information on 9,439 mother-child pairs who received health care through Kaiser Permanente in the Pacific Northwest and Hawaii. All women gave birth between 1995 and 2000, and none had pre-existing diabetes. The women were screened for hyperglycemia, or high blood sugar, and gestational diabetes; their children were measured for weight between the ages of 5 and 7 — what researchers call the adiposity-rebound period, during which excessive weight gain usually predicts adult obesity. Regardless of factors like race or ethnicity, birth weight and maternal weight gain or age, researchers found that the risk of a child becoming overweight rose in step with the mother's blood-sugar level during pregnancy.
Women whose blood-sugar tests indicated gestational diabetes were 89% more likely than other women to have overweight children, and 82% more likely to have obese kids. Women whose blood-sugar readings were at the upper end of normal (122 mg/dl to 140 mg/dl) were still 22% more likely to have overweight children than women at the low end of normal (with blood-sugar levels between 43 mg/dl and 94 mg/dl), and 28% more likely to bear children who become obese. "Even in what's considered normal, in the highest quartile there was an elevation in risk," says Dr. Teresa Hillier, a CHR endocrinologist and senior investigator and lead author of the study. "You could argue, should we consider lowering the criteria? One forty [mg/dl] is the typical cutoff [for diabetes]. Some ppl have argued that it should be 130."