Large for Gestational Age
What is large for gestational age?
Large for gestational age is used to describe newborn babies who weigh more than the usual amount for the number of weeks of pregnancy. Babies are called large for gestational age if they weigh more than 9 in 10 babies of the same gestational age. They are also called large for gestational age if they weigh more than 8 pounds, 13 ounces (3.95 kilograms). The average baby weighs about 7 pounds at birth. About 9 in 100 babies weigh more than 8 pounds, 13 ounces at birth. Rarely do babies weigh more than 10 pounds.
Most babies who are large for gestational age are born at full-term. That is between 37 to 41 weeks of pregnancy. Some premature babies may be large for gestational age.
What causes large for gestational age?
Some babies are large because their parents are large. Parents may pass along this trait to their children. A high birth weight can also be caused by the amount of weight a mother gains during pregnancy. Women who gain a lot of weight during pregnancy often give birth to babies who are large for gestational age.
Diabetes in the mother is the most common cause of babies who are large for gestational age. When a pregnant woman has high blood sugar, she can pass that along to her baby. In response, the baby's body makes insulin. All the extra sugar and the extra insulin that is made can lead to fast growth and deposits of fat. This means a larger baby.
Which babies are at risk for large for gestational age?Because these babies are so large, birth can be difficult. Problems at birth may include:
- Long time for delivery
- Difficult birth
- Injury to the baby, such as a broken collar bone
- Increased need for a cesarean section delivery
- Baby breathes meconium into the lungs around the time of delivery
Many large babies are born to mother with diabetes. Poor control of blood sugar may cause problems such as:
- Low blood sugar in the baby after delivery
- A higher number of birth defects
- Trouble breathing
Many babies who are large for gestational age also have yellowing of the skin, eyes, and mucous membranes (jaundice).
What are the symptoms of large for gestational age?Babies are called large for gestational age if they weigh more than 9 in 10 babies of the same gestational age. In the U.S., this means babies born at 40 weeks' gestation who weigh more than 8 pounds, 13 ounces (3.95 kilograms). Babies who are at the greatest risk for complications weigh more than 9 pounds, 11 ounces (4.34 kilograms) at birth.
How is large for gestational age diagnosed?
Babies with this problem are often diagnosed before birth. During pregnancy, a baby’s size can be guessed in different ways. The height of the top of a mother’s uterus can be measured from the pubic bone. This measurement in centimeters usually links with the number of weeks of pregnancy after the 20th week. If this measurement is high for the number of weeks, the baby may be larger than expected.
Other ways to check the baby’s growth include:
- Ultrasound. This test uses sound waves to create a picture of your baby and the inside of your body. It is a more accurate method of estimating the size of your baby. Measurements can be taken of your baby’s head, belly (abdomen), and upper leg bone to see how fast he or she is growing.
- Your weight gain during pregnancy. This can also affect your baby's size. Gaining a lot of weight during pregnancy may cause your baby to be bigger than normal.
Babies are weighed within the first few hours after birth. The weight is compared with the baby's gestational age and recorded in the medical record.
How is large for gestational age treated?
Treatment will depend on your child’s symptoms, age, and general health. It will also depend on how severe the condition is.
If ultrasound exams during pregnancy show that your baby is very large, some doctors may recommend early delivery. In this case, the doctor may recommend a planned cesarean section.
After delivery, a baby who is large for gestational age will be carefully checked for any injuries that happened during birth. Blood glucose testing is also done to check the baby for low blood sugar.
What are the complications of large for gestational age?
Babies who are large for gestational age are at higher risk for a breathing problem called respiratory distress syndrome. They are also at risk of breathing meconium into the lungs around the time of delivery.
Birth injuries such as a broken collar bone are more common in babies who are large for gestational age. These babies also may need to stay in neonatal intensive care because of breathing problems, low blood sugar (hypoglycemia), and breathing meconium into the lungs. In addition, chances of death are greater in babies who weigh more than 8 pounds, 13 ounces. The risk increases as the birth weight increases.
How can large for gestational age be prevented?Regular prenatal care is important in all pregnancies. Regular checkups can help your healthcare provider find out if your baby is too large. If your baby seems large, it may be a sign that you have undetected diabetes or other problems. To lower some of the risks to your baby:
- Take care of your diabetes.
- Watch your weight.
- Follow your healthcare provider’s advice.
Key points about large for gestational ageBabies are called large for gestational age if they weigh more than 8 pounds, 13 ounces at birth.
- Diabetes is the most common cause of babies who are large for gestational age.
- Because these babies are so large, delivery can be difficult.
- If ultrasound exams during pregnancy show a baby is very large, some doctors may recommend early delivery.
- Regular prenatal checkups can help your healthcare provider find out if your baby is too large.
Tips to help you get the most from a visit to your child’s healthcare provider:
- Know the reason for the visit and what you want to happen.
- Before your visit, write down questions you want answered.
- At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you for your child.
- Know why a new medicine or treatment is prescribed and how it will help your child. Also know what the side effects are.
- Ask if your child’s condition can be treated in other ways.
- Know why a test or procedure is recommended and what the results could mean.
- Know what to expect if your child does not take the medicine or have the test or procedure.
- If your child has a follow-up appointment, write down the date, time, and purpose for that visit.
- Know how you can contact your child’s provider after office hours. This is important if your child becomes ill and you have questions or need advice.