The aim of this study is to determine the accuracy of DHAS SO4 measurement in maternal serum in prediction of labor induction success and also to be compared to preinduction assessment of cervical characteristics which is used as a gold standard. The Bishop score in 1964 was introduced as a method to predict the time from vaginal examination till the onset of spontaneous labor in multiparous women and is derived from the clinical assessment of five factors : cervical ( dilatation, effacement, consistency and position) and station of the presenting part .( Bishop 1964) .Transvaginal ultrasound to assess cervical length of patients undergoing labor induction was performed and resulted in a positive correlation between the clinical assessment of cervical effacement and sonographic measurement of cervical length.The present study supplied evidence to prove that cervical length measurement sonographically can predict the duration of latent phase of labor.