Fetal macrosomia is a term 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. However, the risks associated with fetal macrosomia increase greatly when birth weight is more than 9 pounds 15 ounces (4500 grams).
Fetal macrosomia makes vaginal delivery difficult and puts the baby at risk of injury during birth. Fetal macrosomia also puts the baby at increased risk of health problems after birth.