DefinitionBy Mayo Clinic Staff
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.
However, the risks associated with fetal macrosomia increase greatly when birth weight is more than 9 pounds 15 ounces (4,500 grams).
Fetal macrosomia may complicate vaginal delivery and could put the baby at risk of injury during birth. Fetal macrosomia also puts the baby at increased risk of health problems after birth.
April 16, 2015
- Copel JA, et al. Fetal macrosomia. In: Obstetric Imaging. Philadelphia, Pa.: Saunders Elsevier; 2012. http://www.clinicalkey.com. Accessed Feb. 8, 2015.
- Allen K, et al. Fetal macrosomia. Obstetrics, Gynaecology and Reproductive Medicine. 2013;23:6.
- Chatfield J. ACOG issues guidelines on fetal macrosomia. American Family Physician. 2001;64:169.
- Abramocwicz JS, et al. Fetal macrosomia. http://www.uptodate.com/home. Accessed Feb. 8, 2015.
- Vendittelli F, et al. Is prenatal identification of fetal macrosomia useful? European Journal of Obstetrics & Gynecology and Reproductive Biology. 2012;161:170.
- Negrato CA, et al. Adverse pregnancy outcomes in women with diabetes. 2012;4:41.
- Frequently asked questions. Pregnancy FAQ098. Special tests for monitoring fetal health. American Congress of Obstetricians and Gynecologists. http://www.acog.org/Patients/FAQs/Special-Tests-for-Monitoring-Fetal-Health . Accessed Feb. 10, 2015.
- Koyanagi A, et al. Macrosomia in 23 developing countries: An analysis of a multicountry, facility-based, cross-sectional survey. The Lancet. 2013:381:476.
- Lim CC, et al. Obesity in pregnancy. Best Practice & Research Clinical Obstetrics and Gynaecology. In press. Accessed Feb. 8, 2015.
- Routine prenatal care. Bloomington, Minn.: Institute for Clinical Systems Improvement. https://www.icsi.org/guidelines__more/. Accessed Feb. 8, 2015.
- American College of Obstetricians and Gynecologists (ACOG) Committee on Practice Bulletins — Obstetrics. ACOG Practice Bulletin No. 22: Fetal macrosomia. Obstetrics & Gynecology. 2000;96:1.
- Wick MJ (expert opinion). Mayo Clinic, Rochester, Minn. Feb. 12, 2015.
- Manning FA. The fetal biophysical profile. http://www.uptodate.com/home. Accessed Feb. 12, 2015.