How to Say It: mak-row-SOHM-ee-uh
Macrosomia is when a baby is larger than normal before birth. Most babies are about 7 pounds (3.17 kilograms). Babies with this health problem are 8 pounds, 13 ounces (3.99 kilograms) or more.
The most common cause is diabetes in the mother during pregnancy.
Things that may raise the risk are:
The main sign is a predicted birth weight of at least 8 pounds, 13 ounces or more.
The doctor will ask about your symptoms and health history. A physical and pelvic exam will be done.
Pictures may be taken to estimate the birth weight. This can be done with ultrasound.
Ultrasound of Fetus
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The goal of treatment is to safely deliver the baby. The baby may be too large to be delivered through the birth canal. A Cesarean delivery (C-section) may be done.
To lower the risk of this problem:
American Congress of Obstetricians and Gynecologists
Centers for Disease Control and Prevention
Women's Health Matters
Society of Obstetricians and Gynaecologists of Canada
American College of Obstetricians and Gynecologists Committee on Practice Bulletins—Obstetrics. Practice Bulletin No. 190: Gestational Diabetes Mellitus. Obstet Gynecol. 2018 Feb;131(2):e49-e64, reaffirmed 2019.
Gestational diabetes mellitus (GDM). EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/gestational-diabetes-mellitus-gdm. Updated July 13, 2018. Accessed August 7, 2018.
6/16/2015: DynaMed Systematic Literature Surveillance https://www.dynamed.com/condition/gestational-diabetes-mellitus-gdm: Wiebe HW, Boulé NG, et al. The effect of supervised prenatal exercise on fetal growth: a meta-analysis. Obstet Gynecol. 2015 May;125(5):1185-1194.
Last reviewed September 2020 by
EBSCO Medical Review Board
Elliot M. Levine, MD, FACOG
Last Updated: 4/27/2021