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Question 1 of 11

The measurement of lecithin in relation to sphingomyelin (L/S ratio) is used to determine fetal lung maturity. Which ratio reflects maturity of the lungs?

Rationale:
A ratio of 2:01 reflects maturity of the lungs. The L/S ratio indicates fetal lung development by measuring surfactant presence; a ratio of 2:1 or higher signifies adequate surfactant, reducing respiratory distress risk. This threshold is widely accepted in clinical practice to confirm the fetus’s readiness for extrauterine life and effective pulmonary function at birth. A: 1.4:1 represents an immature lung state with insufficient surfactant, indicating a higher risk for respiratory complications, thus not meeting the maturity criteria. B: 1.8:1 falls below the established maturity threshold of 2:1, suggesting incomplete lung development and inadequate surfactant levels for optimal neonatal respiration. D: 1:01 indicates a very low lecithin to sphingomyelin ratio, signifying immature lungs and a significant deficiency in surfactant production necessary for breathing after birth.