Foetal lung maturity is assessed by ____________: (A) L/S ratio, (B) Billirubin content of amniotic fluid, (C) Ultrasound, (D) Amniocentesis
Answer is A. The presence of surfactant in amniotic fluid is evident of fetal lung maturity. L/S ratio determines the relative concentration of surfactant. L/S ratio is lecithin to sphingomyelin ratio and should be more than 2. There is an increased risk of respiratory distress syndrome when this ratio is less than 2. Reference : page 516 Textbook of Obstetrics Sheila Balakrishnan 2nd edition