Four-dimensional sonographic assessment of fetal facial expression early in the third trimester

ObjectiveTo evaluate the characteristic patterns of facial expression in fetuses aged from 28 to 34 weeks using 4-dimensional (4-D) ultrasonography.MethodsThe faces of 10 healthy fetuses aged from 28 to 34 weeks were recorded continuously for 15 min with a 4-D ultrasonographic machine performing up to 25 frames per second. The occurrence rates of blinking, mouthing, yawning, tongue expulsion, smiling, scowling, and sucking were evaluated.ResultsMouthing was the most frequent facial expression (median, 6.5; range, 2–19) whereas the least frequent were scowling (median, 1; range, 0–9) and sucking (median, 1; range, 0–2). Mouthing was evident in all fetuses and significantly more frequent than any other movement (P < .05). Yawning (median, 3; range, 0–6), smiling (median, 2; range, 0–9), and blinking (median, 1.5; range, 0–6) were observed in most cases. Tongue expulsion (median, 1.5; range, 0–5), scowling, and sucking were each observed in 6 cases.Conclusion4-D sonography provides a means of evaluating fetal facial expression early in the third trimester. It may be a key to predicting fetal brain function and well-being and an important modality in future fetal neurophysiologic research.