Ultrasound (US) is the standard modality for fetal imaging. It has the advantage of cost-effectiveness, ease, speed of use and patient acceptability. Several parameters based on two-dimensional ultrasonography (2DUS) have been described for the prediction of lung volume including : chest circumference – heart circumference, lung diameter/thoracic circumference ratio, lung cross-sectional area/thoracic cross-sectional area ratio and lung area/ head/circumference ratio, moreover fetal lung maturity can be roughly predicted through assessing lung echogenecity, however two-dimensional (2D) biometric indices are late indicators of pulmonary hypoplasia, and do not have satisfactory sensitivity and specificity for clinical use. The introduction of three dimensional ultrasonography (3DUS) allowed a more accurate assessment of objects with irregular shapes.