To compare the usefulness of a lamellar body count, a fluorescence polarization assay, and the foam stability index for predicting neonatal lung maturity in high-risk pregnancies. This study was conducted at the Department of Obstetrics and Gynecology and the Department of Pediatrics, Assiut University Hospital. A prospective clinical trail. This study was performed after recruiting 73 pregnant women, 52 with high-risk pregnancies (25 had diabetes and 27 had premature labor) and 21 with a healthy full-term singleton pregnancy as controls. All women were delivered in the Department of Obstetrics and Gynecology of Assiut University Hospital. The newborns with respiratory distress syndrome (RDS) were admitted in the neonatal intensive care unit of the Department of Pediatrics. Amniotic fluid specimens were obtained near delivery. Apgar score, vital signs, anthropometric data, and complete clinical examination results were available for all newborns, and particular emphasis was placed on signs of RDS. The incidence of RDS was 44.2% in the newborns of women who had experienced a high-risk pregnancy (of these, 82.6% were born preterm and 17.4% to diabetic mothers). We found that a lamellar body count is a good screening test for predicting neonatal lung maturity. It is as good as the fetal lung maturity assay by fluorescence polarization in some respects and better in others; moreover, it is better than the foam stability index test in all respects. A lamellar body count with cutoffs of 41 x 10(3)/microL and 18 x 10(3)/microL was a good predictor of low and high risks of RDS in newborns. Values between 19 x 10(3)/microL and 40 x 10(3)/microL were the best to predict an intermediate risk of RDS. Lamellar body count is a good screening test for predicting the degree of neonatal lung maturity.