Amniotic fluid: [L/S ratio] or [lecithin] or [sphingomyelin] (finding)
amniotic fluid: [l/s ratio] or [lecithin] or [sphingomyelin] (finding)
Amniotic fluid: [L/S ratio] or [lecithin] or [sphingomyelin] (finding)
amniotic fluid: [l/s ratio] or [lecithin] or [sphingomyelin] (finding)