Large for Gestational Age Baby

Large for gestational age (LGA) is a medical term that describes a baby's size. An LGA baby is bigger than other babies who are the same age. It can describe a baby still in the mother's womb or a newborn baby. If the baby is still in the mother's womb, the baby is considered to be an LGA baby if it is bigger than 90% of other babies who are at the same week of pregnancy (gestational age). An LGA newborn weighs more than 8 pounds 13 ounces at birth.


Different things may affect whether a baby is bigger than normal. These things include:

  • The mother developing diabetes during pregnancy (gestational diabetes).

  • The mother having diabetes before becoming pregnant.

  • A prolonged pregnancy.

  • The mother's pre-pregnancy weight.

  • Excessive maternal weight gain (more than 35 pounds during pregnancy).

  • Genetics.

  • The age of the mother.


An LGA baby has a higher risk of injury during birth and complications after birth. Risks and complications to the mother include:

  • Prolonged childbirth.

  • Vaginal tearing.

  • The need for a cesarean delivery.

Risks and complications to the baby include:

  • Birth injury, such as a shoulder injury.

  • Breathing troubles after birth.

  • Low blood sugar (hypoglycemia) after birth.

  • Yellow skin and whites of the eyes (jaundice) after birth.

  • Developing blood sugar problems or diabetes later in life.


Caregivers will carefully watch pregnant women who are more likely to have an LGA baby. This includes women who have diabetes when they become pregnant and women who develop gestational diabetes. It also includes women who are overweight and those who have had an LGA baby before. In order to tell if you may have an LGA baby, a caregiver may:

  • Keep track of how much weight you gain.

  • Check the size of your uterus. This is done by measuring from your pubic bone to the highest part of your belly.

  • Perform a fetal ultrasound to estimate the baby's weight.


Before childbirth:

  • If you have diabetes, you may need to change your exercise and eating habits. The goal is to keep you from gaining too much weight and to control your blood sugar levels.

  • You may need to take medicine to lower your blood sugar.

  • Your baby's size and heartbeat will be checked. This will happen more often as your due date gets closer.

  • Your caregivers may suggest that labor be induced or suggest a cesarean delivery. This advice is often given if your baby appears to be large.

After delivery:

  • The baby will be given a blood sugar test. Blood sugar testing will be done to check for low blood sugar levels. This test may be repeated several times.

  • Babies with low blood sugar may need to be fed earlier and more frequently.

  • Most babies will not have major problems because of their large size. They can be sent home with regular instructions for newborn care.


If your caregiver thinks you may give birth to an LGA baby, it is important to make sure you get good prenatal care. If you have been diagnosed with diabetes during pregnancy:

  • Eat a balanced diet. This should include plenty of fruits, vegetables, and whole grains.

  • Eat small meals several times a day. This can prevent spikes and dips in blood sugar.

  • Avoid soft drinks and foods that contain a lot of sugar.

  • Exercise. Try walking a little bit each day.

  • Ask your caregiver if you should take prenatal vitamins.