Phosphatidylglycerol and fetal lung maturity

The lecithin/sphingomyelin (L/S) ratio has been reported to be inadequate as a predictor of fetal surfactant maturity in many complicated obstetric cases, particularly in patients with diabetes. L/S ratios are also unreliable when the sample contains blood or meconium. Phosphatidylglycerol (PG) is present only in amniotic fluid and respiratory tract effluent. PG may characterize surfactant maturity in samples of amniotic fluid contaminated with blood or meconium as well as specimens collected from the vagina in cases of premature rupture of membranes. Three hundred eleven samples of amniotic fluid collected from January, 1980, to June, 1981, were analyzed for L/S ratio and PG. This report analyses the ability of these tests to predict neonatal maturity in normal and complicated obstetric cases.