Laboratory testing for the assessment of fetal lung maturity includes all of the following tests except

Laboratory testing for the assessment of fetal lung maturity includes all of the following tests except

• A. Acetylcholinesterase
• B. L/S ratio
• C. Fluorescence polarization
• D. Foam stability

Answer: (A)

Fetal lung maturity is assessed by measuring markers of surfactant production and function in amniotic fluid because surfactant reduces surface tension in the lungs after birth. The most established test is the lecithin-to-sphingomyelin (L/S) ratio, since lecithin increases with gestation while sphingomyelin stays relatively steady; a ratio around 2:1 or higher suggests mature lungs and lower risk of respiratory distress syndrome. Another indicator is the presence of phosphatidylglycerol, which appears later in gestation and supports maturity when detected. Foam stability testing examines how well the amniotic fluid maintains foam after agitation—a stable foam points to adequate surfactant. Fluorescence polarization assays provide a measure related to surfactant phospholipids by analyzing fluorescence properties that reflect surfactant content. Acetylcholinesterase, however, is not used to assess fetal lung maturity. In amniotic fluid, it serves as a marker for neural tube defect screening and related conditions, not surfactant function or lung development.

Fetal lung maturity is assessed by measuring markers of surfactant production and function in amniotic fluid because surfactant reduces surface tension in the lungs after birth. The most established test is the lecithin-to-sphingomyelin (L/S) ratio, since lecithin increases with gestation while sphingomyelin stays relatively steady; a ratio around 2:1 or higher suggests mature lungs and lower risk of respiratory distress syndrome. Another indicator is the presence of phosphatidylglycerol, which appears later in gestation and supports maturity when detected. Foam stability testing examines how well the amniotic fluid maintains foam after agitation—a stable foam points to adequate surfactant. Fluorescence polarization assays provide a measure related to surfactant phospholipids by analyzing fluorescence properties that reflect surfactant content.

Acetylcholinesterase, however, is not used to assess fetal lung maturity. In amniotic fluid, it serves as a marker for neural tube defect screening and related conditions, not surfactant function or lung development.