Pregnancy Ultrasound Explained: 3D/4D Scans, Fetal Doppler and What Each One Is For

Pregnancy ultrasound is one of the most familiar forms of medical imaging, but the different types are often misunderstood.

Terms such as 3D, 4D and Doppler describe different capabilities, each with a clinical purpose.

Ultrasound uses sound, not radiation

Ultrasound creates images using high-frequency sound waves. It does not use ionising radiation, which is one reason it is widely used in pregnancy.

Conventional ultrasound

Standard two-dimensional ultrasound produces cross-sectional images in real time.

It remains the principal tool for assessment during pregnancy, and most clinical measurements are taken from these images.

3D ultrasound

3D ultrasound combines many two-dimensional images into a volume, which can be viewed as a surface image.

It can provide additional detail in certain circumstances, depending on what a clinician needs to assess.

4D ultrasound

4D ultrasound adds movement, showing the volume changing over time rather than as a still image.

Rapid Diagnostics provides 3D and 4D ultrasound as part of its advanced ultrasound services.

Fetal Doppler

Doppler ultrasound assesses blood flow.

In pregnancy, fetal Doppler may be used to provide information about circulation where a clinician considers it appropriate.

It answers a different question from a standard scan, which is why the two are not interchangeable.

A scan is a medical examination

Pregnancy scans are often a memorable experience, and the images can be meaningful for parents.

However, the purpose of the examination is clinical assessment. Which scan is appropriate, and when, is determined by the healthcare professional responsible for your care.

Preparation

Some scans require a full bladder, and requirements vary by examination and stage of pregnancy.

Instructions specific to your scan are provided when your appointment is booked.

Rapid Diagnostics provides 3D/4D ultrasound and fetal Doppler across its imaging services.