Fetal lung maturity is assessed by all of the following except: September 2007

Ans. C: Maternal alpha feto-protein level The two earliest tests that were introduced in the 1970's to assess fetal lung maturity were: The lecithin/sphingomyelin (L/S) ratio Detection of phosphatidylyglycerol Originally, both of these tests were performed by thin-layer chromatography (TLC), a technique that required considerable expeise and was both time-consuming and expensive to perform. In the early 1990's another test was developed. The TDx-FLM assay : This test employs fluorescence polarization to measure the ratio of surfactant to albumin (S/ A) in uncentrifuged amniotic fluid. It is simple, quantitative, can be performed in 60 minutes or less and is highly reproducible. TDx-FLM results correlate well with the L/S ratio and PG and with clinical outcomes. Another simple, rapid, and accurate test that can be performed on amniotic fluid to assess fetal lung maturity is the lamellar body (LB) count. LB are made by the type II cells in the alveoli that produce surfactant and, indeed, they are the packages in which surfactant is stored. They are released into the amniotic fluid from the lungs in increasing quantities that parallel surfactant production. Another test actually measures the functional capacity of the surfactants that are present in the amniotic fluid. This test is called the foam stability index (FSI). It too is simple, inexpensive, and can be rapidly performed.