title: Comparison of the fetogram and L/S ratio for fetal maturity.
abstract: There were 254 cases studied in which two tests of fetal maturity were performed within 72 hours of each other. The two tests were an x-ray fetogram and an amniotic fluid L/S ratio determination. All fetograms were read by one author for the presence of distal femoral epiphysis (DFE). It was assumed that DFE permits estimation of fetal bone maturation and L/S ratio permits estimation of fetal lung maturity. The DFE results gave a 40% false-positive rate in predicting a mature L/S ratio (greater than 2.0) and a 38.7% false-negative rate. Of the 21 patients who delivered within 3 days of the performance of the two tests, all neonates did well when there were no visible DFE's but a mature L/S ratio. There is a significant lack of specificity and sensitivity of the fetogram DFE's in predicting a mature L/S ratio. Since infant lung maturation is a critical factor in predicting neonatal survival, these results suggest that the x-ray DFE is unacceptable as a single maturity test for use in a perinatal center managing complicated obstetric cases.
mesh_terms: D000653:Amniotic Fluid / Q000032:analysis*; D001724:Birth Weight; D004838:Epiphyses / Q000000981:diagnostic imaging* / Q000196:embryology; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D005269:Femur / Q000196:embryology; D005333:Fetus / Q000502:physiology*; D006801:Humans; D007231:Infant, Newborn; D010713:Phosphatidylcholines / Q000032:analysis*; D011247:Pregnancy; D011248:Pregnancy Complications; D011859:Radiography; D012127:Respiratory Distress Syndrome, Newborn / Q000175:diagnosis; D013109:Sphingomyelins / Q000032:analysis*
chemical_list: D010713:Phosphatidylcholines; D013109:Sphingomyelins