 Literature has suggested that activation of the fetal hypothalamic-pituitary-adrenal axis play a crucial rule in commencement of labor. Norwitz et al, 1999 A previous study demonstrated that three -dimensional ultrasound measurement of fetal adrenal gland volume AGV may identify women at risk for impending PTB. Turan et al, 2007 In a more recent study receiver operator characteristics ROC curve analysis revealed that three -dimensional ultrasound measurement of AGV was superior to two-dimensional ultrasound measurement of AGV for anticipation of PTB within 7 days of the scan. Turan et al, 2012 The aim of this study is to investigate the utility of 3D fetal adrenal gland volume measurement in the early prediction of PTB and to determine whether these measurements could be combined with 2D ultrasound cervical assessment to improve the early prediction of PTB. 