The term "fetal macrosomia" is used to describe a newborn who's significantly larger than average. A baby diagnosed with fetal macrosomia has a birth weight of more than 8 pounds, 13 ounces (4,000 grams), regardless of his or her gestational age. About 9 percent of babies born worldwide weigh more than 8 pounds, 13 ounces
Fetal macrosomia also puts the baby at increased risk of health problems after birth. Fetal macrosomia can be caused by genetic factors as well as maternal conditions, such as obesity or diabetes.
In most cases, no treatment is needed for a baby with macrosomia. Problems that may occur for the mother include the ripping of the perineum at the time of delivery, the need to reduce blood sugar levels, and the need to lower blood pressure.