Significance of phosphatidylglycerol in amniotic fluid in complicated pregnancies

In normal pregnancy lecithin/sphingomyelin ratios correlate with gestational age. In complicated pregnancies biochemical maturation of fetal lung may be accelerated or delayed, depending upon maternal, fetal, or placental conditions. Surfactant contains other phospholipids besides lecithin, including phosphatidylglycerol (PG), the second major component of mature surfactant. Ninety phospholipid patterns in amniotic fluid were studied by two-dimensional thin-layer chromatography. In uncomplicated pregnancies PG was absent until 37 weeks' gestation, then increased thereafter. In complicated pregnancies (pre-eclampsia, diabetes Classes D, F, and R, premature rupture of membranes) PG was identified before 35 (as early as 29) weeks' gestation. These results verify accelerated lung maturation in certain complicated pregnancies. No newborn infant developed respiratory distress syndrome in the presence of PG.