What is a 4D ultrasound?
A standard (2D) ultrasound shows the baby in cross-sections. 3D ultrasound builds a surface image from these sections; 4D ultrasound presents this surface image in real time and in motion. The baby’s facial features and hand and foot movements can be seen.
At which weeks is it done?
For a 4D image, the period from the middle of the second trimester to the start of the third trimester is generally preferred. In earlier weeks the baby’s facial features are not yet clear; in very late weeks the baby has grown and has less room to move, so seeing the face can become harder. The suitable week for you is decided at the appointment.
How it differs from a detailed ultrasound
A detailed ultrasound is a medical assessment in which the baby’s organs and development are examined systematically, and it is mostly done with two-dimensional images. A 4D ultrasound mostly offers a surface image. Both can be done in the same session; however, a 4D image does not replace a detailed examination.
What affects the image?
The baby’s position, the amount of amniotic fluid, the position of the placenta and the thickness of the abdominal wall affect image quality. If the baby has turned their face away or is covering it with their hands, a clear image may not be possible that day. In that case you may need to walk around for a while or postpone the scan to another day.
Is it safe?
Ultrasound works with sound waves and does not involve radiation. In pregnancy, ultrasound is a widely used method when it is performed by a doctor for a medical reason and for only as long as needed. You are welcome to ask any questions at the appointment.
This article is for general information only; an examination is needed for personal diagnosis and treatment.
