The term macrosomia is used to describe a newborn with an excessive birth weight. A diagnosis of fetal macrosomia can be made only by measuring birth weight after delivery; therefore, the condition is confirmed only retrospectively, ie, after delivery of the neonate. Fetal macrosomia is encountered in up to 10% of deliveries.
Fetal macrosomia is difficult to detect and diagnose during pregnancy. Possible signs and symptoms include: During prenatal visits, your health care provider might measure your fundal height the distance from the top of your uterus to your pubic bone. A fundal height that measures larger than expected could be a sign of fetal macrosomia, Too much amniotic fluid the fluid that surrounds and protects a baby during pregnancy might be a sign that your baby is larger than average.
The pathophysiology of macrosomia is related to the associated maternal or fetal condition that accounts for its development. In general, poorly controlled diabetes, maternal obesity, and excessive maternal weight gain are all associated with macrosomia and have intermittent periods of hyperglycemia in common. Hyperglycemia in the fetus results in the stimulation of insulin, insulinlike growth factors, growth hormone, and other growth factors, which, in turn, stimulate fetal growth and deposition of fat and glycogen.
Variation in the percentage of macrosomia in different ethnic groups has been observed independent of diabetes. In general, Hispanic women have a larger proportion of macrosomic newborns compared with white, African American, or Asian women.