Doctors have long known gestational diabetes harms babies. But what about milder high blood sugar during pregnancy? 
A new study published in the Journal of Clinical Endocrinology & Metabolism looked at 27,876 children from 23,334 normal glucose mothers, 3,413 with gestational glucose intolerance (GGI), and 1,129 with gestational diabetes (GDM). 
Researchers tracked obesity, i.e., BMI over 95th percentile, at ages 2-5, 6-10, and 11-18. They adjusted for mother’s age, race, weight gain, and more, along with a second check for early pregnancy BMI. The question analyzed in the study was the effect of high blood sugar during pregnancy on the child.
Obesity Rates Climb with Age and Mom's Sugar Levels
Obesity was reported in 13.5% in 2-5 year old, 20.3% in 6-10 year old, and 23.4% in 11-18 year old children. Children from GGI-1 and GDM mothers faced higher odds than normal glucose kids. In 6-10 year old, GDM exposure still raised obesity odds 21% (OR 1.21, 95% CI 1.01-1.46). For teens 11-18, GGI-1 upped it 44% (OR 1.44, 1.14-1.81) and GDM 28% (OR 1.28, 1.03-1.59). Younger children showed trends, but less strong.
Why Mom's Sugar Hits Kids Later
Sugar crosses the placenta easy, feeding baby fat cells and insulin habits. Even one unfavorable test signals risks. Mother’s weight explains part, i.e., overweight moms have overweight kids anyway. 
Tools for Your Prenatal Visits
Next pregnant patient with odd glucose screen? Note GGI risk for her kids. Push 5-10% pre-pregnancy weight loss if overweight. Postpartum, track those children’s BMI at well-child visits. Ages 6+ need extra watch that include diet counseling, activity goals. Family docs and endocrinologists should flag GGI history in charts.
Bigger Steps for Prevention
Screen all pregnancies tighter and educate mothers on chronic effects on sugar. GDM mothers get follow-up and extend this follow-up to mothers with GGI. 
This pushes earlier talks: "Your mild high sugar may mean overweight or obese child—let's act now." Families change habits when risks feel personal.