How does prenatal ultrasound work?
An ultrasound is the interpretation of reflected sound waves to form a picture of the fetus. 2D ultrasound (sometimes referred to as “traditional” ultrasound) has been safely used in obstetrics for over 35 years. 2D ultrasound works by listening to sound waves in a single plain. The ultrasound is directed straight down and reflected back up again. Think of it as being able to virtually slice a loaf of bread. The resulting black and white image is similar to looking at the face of a slice of bread. 3D ultrasounds work by a different process known as “surface rendering”. In this case, the same sound waves used in 2D are sent down this time at different angles. These reflections are interpreted through sophisticated software, and a 3D image of the fetus is instantly created. Using the same “bread” analogy as before, the surface of the loaf is now being examined from the outside. Surface details can now be visualized with remarkable clarity. 4D ultrasound is captured in the same manner as
