 Women with twin pregnancy with transvaginal sonographic cervical length of 20-25 mm at 20-24 weeks gestational age without symptoms, signs or other risk factors of preterm labor will be included in the study. All women will be randomly divided into two groups; one group study group received vaginal progesterone suppositories in a dose of 400 mg daily beginning at 20-24 weeks gestational age study group and the other group received no treatment control group 