What are 3D/4D baby scans?
Ultrasound has been used for many years in pregnancy to see the baby. Scans that are performed in the NHS are usually 2 dimensional (2D) scans & are used to measure baby’s growth and to detect fetal abnormalities.
In an uncomplicated pregnancy these 2D NHS scans are performed twice – usually between 11 to 14 weeks for dating the pregnancy and to sometimes offer Down Syndrome screening, and then at between 18 to 21 weeks for the purposes of confirming normality and excluding structural abnormalities in the fetus.
However, 2D scanning only provides a black and white picture that does not really allow prospective parents to see their baby in a form that they we would recognise as a baby.
Three dimensional (3D) ultrasound begins as a 2D scan, and then switches into a 3D view. This can result in views of the baby which look much more like a baby. If views are very good these can result in pictures that look a bit like a photograph. 3D scans are static.
The fourth dimension in 4D scans is “time” – the computer within the ultrasound machine processes large amounts of data and builds up a moving 3D image. Consequently, 4D allows fetal behaviour such as sucking a thumb, opening mouth, and movement, to be seen in a three dimensional view. Many families find these “bonding” scans a very worthwhile experience in being able to “see” their baby.