Introduction: The aim of our study is to determine prevalence and clinical significance of the presence of amniotic fluid “sludge” among asymptomatic patients at high-risk for spontaneous preterm delivery. Objective: To determine Clinical significance of the presence of amniotic fluid ‘sludge’ in asymptomatic patients at high risk for spontaneous preterm delivery. Material and methods: In this study, 222 patients at high risk for spontaneous preterm delivery were evaluated for the presence of amniotic fluid sludge with ultrasonography at 26–30, and 32–38 gestational weeks; between July 2022 –December2022 in University Hospital. The primary outcomes were defined as preterm delivery before 34 weeks and preterm delivery before 37 weeks. The secondary outcome defined as preterm premature rupture of membranes (PPROM) prior to preterm delivery. Risk factors for preterm delivery defined as AFS, history of preterm delivery. And, these patients were followed up for their delivery weeks and pregnancy outcomes. We defined the high-risk group as the patients possessing one or more of the followings; a history of spontaneous preterm delivery, recent oligohydramnios, polyhydramnios, and amniotic fluid Sludge. Patients with multiple gestations, placenta Previa, fetal anomalies, or symptoms of preterm labor at first examination were excluded. Results: In this study out of 222(100.0%) patients, 58(26.1%) patients had normal to mildly echogenic AFI echogenicity out of these 58 patients, 57 patients delivered preterm, and 1 patient delivered at term. 78(35.1%) patients had moderately echogenic AFI echogenicity out of these 78 patients, 69 patients delivered preterm and 9 patients delivered at term. 86(38.7%) patients had highly echogenic AFI echogenicity out of these 74 patients delivered preterm and 12 patients delivered at term. 86(38.7%) patients had sludge in amniotic fluid, 1 with adequate amniotic fluid, 4 with excessive amniotic fluid, 81 with scanty amniotic fluid and 136(61.3%) patients had no sludge in amniotic fluid but had adequate amniotic fluid. Out of which 113 (50.9%) patients had, normal delivery and 109(49.1%) patients delivered through C-section. Conclusion: Ultrasound assessment of amniotic fluid plays a vital role in the evaluation of fetal well-being especially during the second and third trimesters. Changes in the amniotic fluid volume can affect the pregnancy as these are closely related to fetal anomalies. Our study has shown that an important risk factor for preterm delivery is the amniotic fluid sludge. In our population the prevalence of amniotic fluid sludge was 38.7% which indicates a high risk for preterm delivery. Thus this can be used an independent indicator of high risk pregnancies.