What is a big baby?
The medical term for big baby is macrosomia, which literally means “big body.” Some experts consider a baby to be big when it weighs more than 4,000 grams (8 pounds 13 ounces) at birth, and others say a baby is big if it weighs more than 4,500 grams (9 pounds, 15 ounces). A baby is also called “large for gestational age” if its weight is greater than the 90th percentile at birth (Rouse et al. 1996).
How common are big babies?
Big babies are born to about 1 out of 10 women in the U.S. Overall, 8.7% of all babies born at 39 weeks or later weigh between 8 lbs 13 oz and 9 lbs 15 oz, and 1.7% are born weighing 9 lbs 15 oz or more (U.S. Vital Statistics). You can see the percentages listed separately below for women who are diabetic and not diabetic.
http://evidencebasedbirth.com/evidence-for-induction-or-c-section-for-big-baby/