During the third trimester of pregnancy, growth scans are routinely performed to monitor the development of the fetus. These scans, also known as fetal growth scans, are non-invasive and use ultrasound technology to estimate the size and weight of the fetus.

What is the purpose of a growth scan?

The primary purpose of growth scans is to ensure that the fetus is developing properly and to detect any potential complications, such as growth restriction or macrosomia (a condition where the baby is larger than average). These scans can also provide important information about the amount of amniotic fluid, the position of the baby, and the health of the placenta.

When would you undergo a growth scan?

Growth scans are typically performed between 28 and 40 weeks of gestation, with most women having at least one scan during this period. The timing and frequency of growth scans may vary depending on the mother's medical history, the size of the baby, and any other risk factors that may be present.

What happens during a growth scan?

During a growth scan, the Sonographer or ultrasound technician will measure various parts of the fetus, including the head circumference, abdominal circumference, and femur length. These measurements are used to estimate the fetal weight and compare it to the expected weight based on the gestational age.

In addition to measuring the fetus, growth scans may also include Doppler ultrasound, (if clinically indicated )which is used to assess blood flow to the fetus and placenta. This can provide valuable information about the health of the baby and the placenta, as well as help to identify any potential issues with blood flow.

Limitations of growth scans

While growth scans can provide important information about the health and development of the fetus, they do have some limitations. The estimates of fetal weight based on ultrasound measurements can be inaccurate, and there is a risk of false positives for growth restriction or macrosomia. Additionally, growth scans do not always detect all potential complications, such as cord compression or fetal distress.

In conclusion, growth scans are a useful tool for monitoring fetal development during the third trimester of pregnancy. They can provide important information about the size and weight of the fetus, as well as help to detect any potential complications.