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.
Source: http://www.mayoclinic.com
Fetal macrosomia is difficult to detect and diagnose during pregnancy. Possible signs and symptoms include:
Excessive amniotic fluid (polyhydramnios). Too much amniotic fluid â the fluid that surrounds and protects a baby during pregnancy â might be a sign that your baby is larger than average.
The amount of amniotic fluid reflects your baby's urine output, and a larger baby produces more urine. Some conditions that increase a baby's size might also increase his or her urine output.
Source: http://www.mayoclinic.com
Fetal macrosomia can be caused by genetic factors as well as maternal conditions, such as obesity or diabetes. Rarely, a baby might have a medical condition that speeds fetal growth.
In some cases, what causes a larger than average birth weight remains unexplained.
Source: http://www.mayoclinic.com
Estimating or predicting a baby's birth weight is difficult. A definitive diagnosis of fetal macrosomia can't be made until after the baby is born and weighed.
Keep in mind that any assessment of a baby's size during pregnancy depends on accurate knowledge of his or her gestational age. If a baby is large for his or her gestational age, it's important to confirm whether your projected due date is correct.
If you have risk factors for fetal macrosomia, your health care provider will likely use tests to monitor your baby's health and development, such as:
Ultrasound. Toward the end of your third trimester, your health care provider or another member of your health care team might do an ultrasound to take measurements of parts of your baby's body, such as the head, abdomen and femur. Your health care provider will then plug these measurements into a formula to estimate your baby's weight.
However, the accuracy of ultrasound for predicting fetal macrosomia has been unreliable.
Antenatal testing. If your health care provider suspects fetal macrosomia, he or she might perform antenatal testing, such as a nonstress test or a fetal biophysical profile, to monitor your baby's well-being.
A nonstress test measures the baby's heart rate in response to his or her own movements. A fetal biophysical profile combines nonstress testing with ultrasound to monitor your baby's movement, tone, breathing and volume of amniotic fluid.
If your baby's excess growth is thought to be the result of a maternal condition, your health care provider might recommend antenatal testingâ starting as early as week 32 of pregnancy.
Note that macrosomia alone is not a reason for antenatal testing to monitor your baby's well-being.
Before your baby is born, you might also consider consulting a pediatrician who has expertise in treating babies diagnosed with fetal macrosomia.
Source: http://www.mayoclinic.com
Fetal macrosomia poses health risks for you and your baby â both during pregnancy and after childbirth.
Possible maternal complications of fetal macrosomia might include:
Possible complications of fetal macrosomia for your baby might include:
Metabolic syndrome. If your baby is diagnosed with fetal macrosomia, he or she is at risk of developing metabolic syndrome during childhood.
Metabolic syndrome is a cluster of conditions â increased blood pressure, a high blood sugar level, excess body fat around the waist or abnormal cholesterol levels â that occur together, increasing the risk of heart disease, stroke and diabetes.
Further research is needed to determine whether these effects might increase the risk of adult diabetes, obesity and heart disease.
Source: http://www.mayoclinic.com
You might not be able to prevent fetal macrosomia, but you can promote a healthy pregnancy.
For example:
Source: http://www.mayoclinic.com
If your health care provider suspects fetal macrosomia during your pregnancy, you might feel anxious about childbirth and your baby's health â and worrying can make it hard to take care of yourself.
Consult your health care provider about what you can do to relieve stress and promote your baby's health. Also consider seeking information and support from women who've had babies diagnosed with fetal macrosomia.
Source: http://www.mayoclinic.com
Many factors might increase the risk of fetal macrosomia â some you can control, but others you can't.
For example:
Maternal diabetes. If you had diabetes before pregnancy (pre-gestational diabetes) or you develop diabetes during pregnancy (gestational diabetes), fetal macrosomia is more likely.
If your diabetes is poorly controlled, your baby is likely to have larger shoulders and greater amounts of body fat than would a baby whose mother doesn't have diabetes.
Fetal macrosomia is more likely to be a result of maternal diabetes, obesity or weight gain during pregnancy than other causes. If these risk factors aren't present and fetal macrosomia is suspected, it's possible that your baby might have a rare medical condition that affects fetal growth.
Your health care provider might recommend prenatal diagnostic tests and perhaps a visit with a genetic counselor, depending on the test results.
Source: http://www.mayoclinic.com
We respect your privacy and aim for the best website experience in compliance with local laws. Allowing cookies enables a tailored experience, while disabling them may reduce personalization. For more information, please read our Privacy Policy and Cookie Policy.