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.
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.
Babies born with macrosomia are more likely to have low blood sugar, respiratory distress, and
The most common cause of macrosomia is
in the mother during pregnancy.
Factors that may increase the chance of giving birth to a baby with macrosomia include:
The main sign of macrosomia is a predicted birthweight of at least 8 pounds, 13 ounces or more. This birthweight may be estimated during prenatal testing.
The doctor will ask about your symptoms and medical history. A physical and pelvic examination will be done. An
can help 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.
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.
Monitoring babies with macrosomia for low blood sugar and jaundince, and feeding babies soon after birth are important steps to take to prevent low blood sugar in the baby and prevent and detect neonatal jaundice.
To help prevent macrosomia:
Centers for Disease Control and Prevention
The American Congress of Obstetricians and Gynecologists
The Canadian Women's Health Network
The Society of Obstetricians and Gynaecologists of Canada (SOGC)
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Last reviewed June 2016 by James Cornell, MD
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