Large for Gestational Age Babies – Causes, Symptoms, and Treatment

Measuring the weight of the growing baby is very important in the entire journey of pregnancy. During pregnancy, you need to undergo various scans and checks throughout to determine multiple factors, including the weight of your growing foetus. These checks determine the health and well-being of your baby. Sometimes a baby weighs more as compared to most other babies of the same gestational age when born, and this is termed as large for gestational age babies. In this article, we have covered areas including the causes, symptoms, and treatment of large for gestational age babies.

What Is Large Gestational Age? (LGA)

LGA or Large for Gestational Age babies is a medical term that is used for babies born with more than usual weight corresponding to the number of weeks of pregnancy. Before the birth of the baby, LGA is termed as foetal macrosomia. A typical LGA baby will weigh more than almost 90% of all the babies born with the same gestational age. On average, a baby weighs around 7 pounds when born, and approximately 9% of babies weigh more than 8 pounds. Babies that weigh over 10 pounds are quite rare. In most cases, LGA babies are born between 37 to 41 weeks of pregnancy. However, in rare cases, premature babies may also turn out to be LGA as well.

Important Facts About Large for Gestational Age

Some essential facts about large for gestational age babies include:

• Maternal diabetes is one of the leading causes that babies are born large for their gestational age.
• Babies are termed to be larger for their gestational age if they are overweight as compared to other babies of the same gestational age at birth.
• Normal delivery can be difficult in case of large for gestational age babies.
• The large size of the baby increases the risk of perinatal asphyxia and injury at birth, such as clavicle or extreme long bone fracture.
• If it is detected during an ultrasound that your baby is of large size, then the doctor may recommend early delivery.
• Regular prenatal check-ups with your doctor are highly recommended to find out if your baby is too large.
• If the mother has diabetes, then apart from having large for gestational age baby, the baby is also at a higher risk of respiratory distress syndrome and congenital anomalies.

Which Babies Are At a Higher Risk?

The babies that are too large to fit into the birth canal easily are at a higher risk of being born LGA. The problems during birth may include:

• Difficulty in vaginal birthing
• Longer than usual time for delivery
• Birth injuries such as a broken collar bone or nerve damage
• Caesarean section delivery
• Breathing trouble for the mother
• Comparatively higher risk of birth anomalies
• Low blood sugar level at the time of birth

What Causes Babies to Be LGA?

There can be many reasons for the baby to be LGA. One of the main reasons for the babies to be LGA at birth is if the mother is detected with diabetes. If the mother has a high blood sugar level, then during pregnancy, she can pass on this sugar to the growing foetus. As a result, the baby makes insulin and the extra sugar and insulin lead to faster growth and fat deposit. This is the common cause for larger babies. It also poses a higher risk of having low blood sugar after birth. This is because, after birth, the mother’s blood supply stops, but the baby’s insulin levels are still high.

Another reason for babies to be born LGA is because their parents are large. DNA plays a vital role in the growth of babies. Sometimes during pregnancy, the mother gains a lot of weight, and this can also cause the babies to weigh larger than usual during birth.

Symptoms of LGA

Symptoms of LGA can be difficult to detect and diagnose during pregnancy. The primary sign for babies born large for gestational age is that their weight is more than 9 in 10 babies or 97 of 100 babies born at the same gestational age. A larger than usual fundal height of the foetus is a sign of LGA baby. Presence of more than expected amniotic fluid is also a sign that your baby may be larger than average. LGA babies, when born at 40 weeks of gestation, weigh more than 4000 grams or 9 pounds at birth, which is higher than average.

Risks and Complications in an LGA Baby

The possible risks and complications in a baby born large for gestational age may include:

• Babies born large for gestational age are at a higher risk of developing breathing problems, which is also known as respiratory distress syndrome.
• This situation may also pose a risk of breathing meconium into the lungs at the time of birth.
• Large for gestational age foetus is also at a higher risk of developing low blood sugar, also known as hypoglycemia at the time of birth.
• LGA may also cause birth injuries like damaged nerves in the arm or a broken collar bone.
• Large for gestational age newborns most likely also have an excessive amount of red blood cells, which can be termed as polycythemia, and this may result in jaundice at the time of birth. This happens because the excessive red blood cells break down, and the liver of the baby may not be able to handle the increased amount of bilirubin that needs to be conjugated, causing jaundice.

Diagnosis

LGA infant is often diagnosed before birth, and there are different ways to determine the baby’s size before the delivery. Some of the ways to check the growth of the foetus before delivery include:

1. Prenatal Check-Ups

One of the most common methods is to determine the height of the top of the mother’s uterus, which can be measured from the pubic bone. The measurement is taken in centimetres after the 20th week of pregnancy and should correspond to the gestational age. If the measurement turns out to be higher, then the baby may be larger in size.

2. Ultrasound Scan

This is one of the most accurate methods of determining the size of the baby, as it uses sound waves to create an image of the baby and the insides of the womb. However, an LGA ultrasound is not 100% accurate, but it can give the approximate measurements of the head, belly, abdomen, legs, hands etc. of the baby, and also check the growth of the baby.

3. Weight Gain During Pregnancy

Excessive weight gain during pregnancy can lead to larger than normal baby. Excessive weight gain by the mother can affect the baby’s growth and size.

How Is LGA Treated?

Here is how LGA is treated:

• After the diagnosis, your doctor may recommend an early delivery, if the baby appears to be larger than normal corresponding to the gestational age.
• You may have to undergo a planned C-section. However, the treatment line depends upon the overall health and weight of the baby.
• Once the baby is born, a thorough check will be done by the expert to determine birth injuries, if any.
• The blood glucose level of the baby will be tested for the first 12 hours to check for low blood sugar levels.

How Can This Be Prevented?

Proper prenatal care and regular check-ups are critical in all pregnancies. You try to lower the risk of LGA by continuously keeping a check on your blood sugar levels before and during the pregnancy, watch your diet and weight gain. Regular check-ups with your doctor will help you determine the growth of your baby and other complications like gestational diabetes, etc.

A preconception appointment with your healthcare provider if you have complications like obesity, diabetes, high blood pressure etc. will be extremely beneficial. Prenatal care is critical during pregnancy. Regular monitoring of your blood sugar levels and an active lifestyle will help lower some risks of foetal macrosomia.

Also Read:

Does Gestational Diabetes Affect Your Delivery Options?
How Does Gestational Diabetes Affect Baby and Mother
Gestational Sac while Pregnant