Ultrasound for evaluation of fetal neurobehavioural development: from 2‐D to 4‐D ultrasound

Abstract

Abstract With respect to the assessment of fetal behaviour, there have been numerous reports on the conventional two‐dimensional (2‐D) ultrasonographic evaluation of fetal movements. However, there are some limitations regarding the assessment of fetal movements using 2‐D ultrasound. Because of the 2‐D character of real‐time scanning, fetal movements outside the scanning plane cannot be displayed on the monitor. The advent of three‐dimensional (3‐D) ultrasound significantly advanced fetal and placental evaluation in normal and abnormal pregnancies. The introduction of four‐dimensional (4‐D) ultrasound techniques would allow the assessment of fetal behavioural assessment in three dimensions in real time during pregnancy. We present the latest 4‐D sonographic techniques and recent 4‐D sonographic studies on fetal behaviour, especially fetal whole‐body movements and facial expressions in all three trimesters of pregnancy, and the continuation of behaviour from the fetal to neonatal period. 2‐D does not appear capable or comparable to 4‐D ultrasound in terms of evaluating early fetal facial expressions. Moreover, we describe the safety of 3‐D/4‐D ultrasound during pregnancy. This novel technique may assist in the evaluation of fetal behaviour, and offer potential advantages relative to conventional 2‐D ultrasound. 4‐D ultrasound may be an important modality in future research on fetal neurobehavioural development, although some limitations regarding the assessment of fetal behaviour by means of 4‐D ultrasonography still remain unresolved. Copyright © 2009 John Wiley & Sons, Ltd.