An investigation into the relationship between amniotic fluid sludge in the second trimester of pregnancy and preterm labor

Introduction: Amniotic fluid sludge is an additional ultrasound indicator for preterm labor. Amniotic fluid sludge refers to dense particles near the inner cervical spine. Amniotic fluid 'sludge' is defined as the presence of dense aggregates of particulate matter in close proximity to the internal cervix. It is of clinical significance in asymptomatic patients at high risk for spontaneous delivery, and in patients with preterm labor and intact membranes. Sub-chorionic hematoma is another ultrasound finding that is associated with a higher incidence of threatened miscarriage and preterm delivery. Given the ultrasound imaging features, it is similar to the gallbladder sludge. This study aimed to investigate the relationship between amniotic fluid sludge in the second trimester of pregnancy and preterm labor. Materials and Methods: This cross-sectional, analytical study was carried out on pregnant women with amniotic fluid sludge referring to the radiology clinic. Pregnant women underwent ultrasound and examined if they had amniotic fluid sludge. Accordingly, 347 people were selected. Firstly, characteristics such as age, location, education level, occupation, number of pregnancies, labor, and abortion were completed by a specialized radiologist. The amniotic fluid sludge was investigated within 14-18 weeks, 20-24 weeks and 24-28 weeks. The cervical length was measured at 20-24 weeks and the duration and method of labor were recorded. Finally, the data were analyzed using SPSS (version 20). Results: There was no relationship between preterm labor and the observation of sludge in the second trimester (P = 0.951). There was a relationship between the number of pregnancies and the number of deliveries and the observation of sludge in the second trimester (P = 0.0001). There was a positive relationship between the number of pregnancies and the observation of sludge in the second trimester (r = 0.293). There was a positive relationship between the number of births and the observation of sludge in the second trimester (r = 0.247). Conclusion: There was no relationship between preterm labor and amniotic fluid sludge in the second trimester. Further studies are required in this regard.