• Macrosomia

    (Large for Gestational Age; LGA)


    Macrosomia is a condition in which a baby is abnormally large before birth. The average birth weight for babies is about 7 pounds. Babies with macrosomia have a birth weight of at least 8 pounds, 13 ounces or more.
    Babies born with macrosomia are more likely to have low blood sugar, respiratory distress, and jaundice . They also have an increased risk of birth defects.
    Jaundice Baby
    Jaundice Baby
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    Macrosomia occurs in more than 10% of all pregnancies in the United States. It may lead to pregnancy complications such as a greater risk of cesarean delivery , damage to the birth canal, and injury to the baby during a vaginal delivery.


    The most common cause of macrosomia is diabetes in the mother during pregnancy.

    Risk Factors

    Factors that increase the risk of giving birth to a baby with macrosomia include:
    • Mother having diabetes
    • Mother having gestational diabetes
    • Mother and/or father of large size
    • Excessive weight gain by the mother during pregnancy

    Signs and Symptoms

    The main symptom of macrosomia is a birthweight of at least 8 pounds, 13 ounces or more. This birthweight may be estimated during prenatal testing.


    Your doctor will ask about your symptoms and medical history. A physical and pelvic examination will be done. An ultrasound will be done to determine the size of the baby before birth.
    Your doctor will estimate the birth weight and evaluate any dangers for the mother and/or baby.
    If the fetal macrosomia may cause potential harm during a vaginal delivery, a Cesarean delivery may be scheduled.
    Ultrasound of Fetus
    Fetal Ultrasound
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    Talk with your doctor about the best treatment plan for you. Treatment options include:

    Cesarean Delivery

    Recommended for babies too large to be safely delivered through the birth canal.
    Feeding babies with macrosomia soon after birth is important to prevent low blood sugar in the baby.
    Feeding babies with macrosomia soon after birth is important to prevent low blood sugar in the baby.


    Macrosomia may not always be prevented. Some steps that may help include: .
    • Maintaining a healthy weight throughout pregnancy
    • Controlling blood sugar if you have diabetes
    • Receiving prenatal care to diagnose problems early and prevent complications


    The American Congress of Obstetricians and Gynecologists http://www.acog.org

    Centers for Disease Control and Prevention http://www.cdc.gov

    National Institute of Child Health & Human Development http://www.nichd.nih.gov


    British Columbia Ministry of Health http://bchealthguide.org

    The Society of Obstetricians and Gynaecologists of Canada http://www.sogc.org


    Gestational diabetes mellitus (GDM). EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed . Updated August 27, 2012. Accessed October 4, 2012.

    Heiskanen N, Raatikainen K, Heinonen S. Fetal macrosomia—a continuing obstetric challenge. Biology of the Neonate . 2006;90(2):98-103. Epub 2006 Mar 16.

    Zamorski MA, Biggs WS. Management of suspected fetal macrosomia. Am Fam Physician . 2001 Jan 15;63(2):302–307. Available at: http://www.aafp.org/afp/20010115/302.html .

    Revision Information

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