What is a growth scan?

A growth scan, also known as a fetal growth scan, is an ultrasound exam conducted during the third trimester of pregnancy to check for the baby’s size, position, and complications, if any. Your physician will recommend this scan based on your status during the third trimester.

What happens during a growth scan?

During a growth scan ultrasound, various measurements of your baby will be taken by your physician to assess your baby’s growth and size. These measurements are plotted across a growth chart based on the number of weeks of your pregnancy.

The type of measurements taken include:

• Biparietal diameter - measures across the head
• Head circumference - measures around the head
• Abdominal circumference - measures around the abdomen
• Femur length - measures the length of the thigh bone

Why is a growth scan report essential?

With the help of the above measurements, the estimated weight of the baby can be calculated. This weight can be plotted on a graph to assess whether the baby is small, large or normal for its gestational age.

It should be kept in mind that the estimated fetal weight can show an error of up to 20% even with repeated measurements. In such cases, further tests may be done.
Growth scan during pregnancy also records the position of the baby and placenta, the amount of amniotic fluid, and the baby’s activities.

Who needs a growth scan during pregnancy?

• Previous complications: If you have had complications with your previous pregnancy, a growth scan may be recommended as a precaution.
• Multiple fetuses: Pregnancies with multiple fetuses, e.g., twins or triplets, are trickier to manage and may lead to complications. Your physician may recommend a growth scan to check whether everything is in place.
• Conditions like gestational diabetes or hypertension can affect the volume of the amniotic fluid and the baby’s growth. A growth scan during pregnancy will help in monitoring the baby’s growth in mothers with such a condition.
• Your physician may also recommend  a growth scan as a precaution against other potential complications.

Also read: What Is Intrauterine Growth Restriction? (IUGR)