1 Department of Reproductive Biology, Department of Pediatrics, Case Western Reserve University, Perinatal Clinical Research Center, Cleveland Metropolitan General Hospital, 3395 Scranton Road, Cleveland, Ohio 44109
The proportion of lecithin (L) to sphingomyelin (S) measured in amniotic fluid has been proposed as an index of fetal lung maturity.1 A ratio of L to S of 1.5 or less has been correlated with hyaline membrane disease in the postnatal period. Therefore, prevention or delay of immediate delivery has been advocated in such circumstances.
In our laboratory, the L to S ratio (L/S) was determined immediately before birth in 88 amniotic fluid samples obtained by amniocentesis between the 8th and 46th week of gestation.