Background: Preterm labour is a major health challenge in obstetrics. Many risk factors being identified, the most common one is short cervical length, can be diagnosed by transvaginal ultrasound scan after 13 weeks of pregnancy. Vaginal progesterone is the most bioavailable form of progesterone that have effect on uterine and cervix. Progesterone is found to inhibit the production of proinflammatory cytokines and prostaglandins within the uterus and to inhibit myometrial contractility Aim:To evaluate the efficacy of vaginal progesterone administration for preventing preterm birth and decrease perinatal morbidity and mortality in asymptomatic women with a singleton gestation and a mid-trimester sonographic cervical length (CL) ≤ 25 mm. Materials And Methods:This is a prospective study of asymptomatic women with a singleton pregnancy and a sonographic short cervix (<25mm) at 19 + 0 to 23 + 6 weeks of gestation. Women were allocated randomly to receive vaginal progesterone or placebo daily starting from 19 + 0 to 23 + 6 weeks until 36 + 6 weeks, rupture of membranes or delivery, whichever occurred first. Randomization sequence was stratified by centre and history of a previous preterm birth. The primary endpoint was preterm birth before 33 weeks of gestation. Analysis was by intention to treat. Results:Out of 100 patients for whom study was done, 20 lost to followup and remaining divided into two groups: 40 Singleton pregnant women with CL<25mm between 19 + 0 to 23 + 6 weeks of gestation with no sign and symptoms were given daily vaginal progesterone for up to 36 + 6 weeks, rupture of membranes or delivery, whichever occurred first. The dose is 200 mg once daily and a group of 40 women with cervical length of <25 mm between 19 + 0 to 23 + 6 weeks of pregnancy were given no treatment, Maximum distribution belongs to age of 19-24 years followed by 30-34 years. Most of women in this study have no history of preterm labour. In those who received vaginal progesterone 5 women had history of previous preterm labour and five women in no treatment group. It was found that there was statistically significant reduction in preterm labour in women with short cervix <2.5cm with 200mg vaginal progesterone. Conclusions:This updated systematic review and meta-analysis reaffirms that vaginal progesterone reduces the risk of preterm birth and neonatal morbidity and mortality in women with a singleton gestation and a mid-trimester CL ≤ 25 mm, without any deleterious effects on neurodevelopmental outcome. Clinicians should continue to perform universal transvaginal CL screening at 19 + 0 to 23 + 6 weeks of gestation in women with a singleton gestation and to offer vaginal progesterone to those with a CL ≤ 25 mm.