The study is carried on 65 pregnant patients attending the outpatient clinics and inpatient department of Obstetrics and Gynecology of Al Assad University Hospital from February- 2013 until February- 2014. They were divided to three groups. The first is preterm labor with intact membranes (25 patients). The second is PROM (20 patients). The third one is control group (20 patients). All of them were submitted to ultrasonography to find cervical changes (cervical canal length and diameter of internal os in order to predict preterm delivery. Cervical canal length has a sensitivity of 91.43%, a specificity of 100%, a positive predictive value of 100%, a negative predictive value of 76.92%, and a relative risk (95% CI) of 4.33 (1.61-11.69) among patients with short cervical canal length and those with normal cervix. Diameter of internal os as a predictor of preterm delivery has a sensitivity of 60%, a specificity of 60%, a positive predictive value of 84%, a negative predictive value of 30%, and a relative risk (95% CI) of 1.2 (0.86–1.68).