Sonographically homogeneous echogenic amniotic fluid in detecting meconium-stained amniotic fluid.

A prospective study was performed to examine the hypothesis that sonographically homogeneous echogenic amniotic fluid (AF) may provide a marker for the presence of meconium-stained AF. Twenty term gestations in which homogeneous echogenic AF was demonstrated sonographically were compared with 40 cases with sonographically clear AF. Two cases in the study group had meconium-stained AF at delivery. All of the controls had clear fluid by amniocentesis (performed for lung maturation studies) immediately after the sonographic examination. Thus, homogeneous echogenic AF had a sensitivity of 100%, a specificity of 69%, a positive predictive value of 10%, and a negative predictive value of 100% in detecting meconium. We conclude that homogeneous echogenic AF does not necessarily detect meconium-stained AF.