Health Library

Macrosomia

(Large for Gestational Age; LGA)

Pronounced: mak-row-SOHM-ee-uh

Definition

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

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.

Causes

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.

Diagnosis

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

Treatment

Talk with your doctor about the best treatment plan for you. Treatment options include:

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.

Prevention

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.

Last reviewed September 2012 by Andrea Chisholm

Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.