Preterm birth (PTB) refers to a birth that occurs before 37 weeks of gestation. Preterm babies are premature. The diagnosis of PTB is challenging problem, two new methods for diagnosis of PTB were introduced CT by transvaginal sonography and fetal fibronectin in cervicovaginal secretions. We studied these two methods for prediction of PTB in symptomatic patients with singleton pregnancy within one week. We conclude that both tests are better than previous methods.