4D ultrasound is a type of ultrasound that obtains a sequence of three-dimensional images in 3D. The characteristic feature is that these images are in motion and in real time, which allows a better assessment of fetal activity. For this reason, 4D ultrasound is widely used by specialists in Gynecology and Obstetrics.
4D ultrasound: when to do it?
4D ultrasound can be performed at any gestational stage within the period from 12 weeks to late in the third trimester. However, it is advisable to perform this type of ultrasound between weeks 24 and 32, and ideally between weeks 26 and 28.
If the ultrasound is performed after 32 weeks, it is very likely that the fetus is below the largest diameter of the maternal pelvis and therefore it is very difficult to obtain 3D and 4D images.
The patient should come to undergo the test having eaten some food, i.e., avoiding fasting. It is important to avoid skin creams, because they create an interface with the gel used to perform the ultrasound and this could decrease the quality of the images.
Advantages of 4D ultrasound
To perform a 4D ultrasound, the same physical principle is used as when performing conventional ultrasound, so it is a harmless method for both the mother and the fetus.
The main advantage of 4D ultrasound is that it allows a very high image quality to be obtained, which makes it possible to accurately assess fetal morphology and dynamics, as well as the parameters of the fetal biophysical profile.
This test allows to visualize with great precision the fetal volumes facilitating the detection of malformations, as well as to evaluate all the structures surrounding the fetus such as the amniotic fluid, the umbilical cord and the placenta.
All the images obtained as a result of the 4D ultrasound are recorded so that they can later be reproduced for family and friends. In addition, this is also useful for other specialists to view the images and evaluate the fetal morphology study in order to resolve possible doubts.
Performing a 4D ultrasound during pregnancy does not replace the traditional 2D ultrasound performed during the first trimester to screen for aneuploidy. Nor does it replace the 2D ultrasound performed during the 20-22nd week, which is used for fetal morphology studies.
An additional advantage is that it is a much easier ultrasound for parents to understand, which can mean a plus in the peace of mind of both parents when assessing the integrity and welfare of their child, meaning a positive impact both psychologically and emotionally.