The role of amniotic fluid phospholipids in determining fetal lung maturity.

Assessment of the status of amniotic fluid phospholipids (qualitative and semi-quantitative) has become important in determining fetal lung maturity. In uncomplicated pregnancies, it has been documented that the ratio of lecithin to sphingomyelin (L/S ratio), with respect to pediatric gestational age, is a reliable predictor of maturity. In complicated pregnancies (e.g., toxemia, diabetes mellitus) the L/S ratio may result in erroneous clinical interpretation and premature intervention. The presence of phosphatidyl-glycerol (PG) in these cases has been acknowledge to be a significant factor indicative of fetal lung maturity. Thin-layer chromatography, which clearly elucidates the six phospholipids of amniotic fluid, is the method of choice.