Study Design : A prospective observational study. Setting : The study was conducted at Department of Obstetrics & Gynecology at Benha University Hospital during the period from October 2014 through August 2016 .
Objective : To compare between five non-invasive ultrasound parameters as possible markers for predicting fetal lung maturity (FLM).These parameters were : Uterine artery resistance index (Ut RI) , Fetal thalamic echogenicity , Biparietal diameter length , Amniotic Fluid free-floating Particles and Placental changes (Grading-system).
Patient and Methods: Our study included 150 pregnant women who have been admitted for cesarean delivery. All patients were examined by two dimensional ultrasound equipped with Doppler system at Ultrasound Unit in the same day of their elective cesarean section. During ultrasound examination , we looked for the previously mentioned five ultrasound parameters .A biparietal diameter above 92 mm indicated maturity. Also , presence of amniotic fluid free-floating particles indicated maturity. Considering Grannum grading criteria : placental calcification grade II and III indicated maturity. If the echogenicity of the thalamus appeared like brain tissue, it was considered echogenic (indicating maturity), while if it appeared without echoes inside the thalamus it was echolucent (indicating immaturity). Uterine artery Doppler : (Ut RI)values (> 0.64) was a predictor of respiratory distress syndrome (RDS). The results of all five U/S parameters have been compared to neonatal outcomes determined by the attending neonatologist. Results: A mean Ut RI > 0.64 is correlated with delayed FLM ( sensitivity: 83.64%,specificity: 91.58%; positive predictive value: 85.19%, negative predictive value: 90.62%).The presence of echogenic thalamus as a sign of FLM has a specificity of 86.41 % which is higher than other conventional ultrasound signs (sensitivity: 80.85%, positive predictive value: 73.08%, negative predictive value: 90.82%). Conclusion: In third trimester pregnancies, Ut RI has the highest sensitivity and specificity predictive results for FLM. Thalamic echogenicity has comparable results to uterine artery Doppler. Using both together, sensitivity reaches 97%. |
