Phosphatidylinositol and phosphatidylglycerol in amniotic fluid: Indices of lung maturity

Determination of fetal lung maturity by L/S ratio, “shake test” and phosphatidylglycerol in amniotic fluid.

“…Recently, studies on the perinatal development of lung surfactant in the rat and human [8,9] revealed that, besides lecithin, the lung surfactant complex contains other minor characteristic phospholipids. Phosphatidylglycerol (PG) and phosphatidylinositol have been identified.…”

Surfactant Phospholipid Metabolism in 3-Day and 3-Day Postmature Rabbits In Vivo

“…Specifically, high relative amounts of phosphatidylinositol in the amniotic fluid of the fetus (18) or tracheal aspirate (16) of an infant with respiratory distress syndrome indicates a maturing lung. The presence of phosphatidylglycerol in amniotic fluid assures that the respiratory distress syndrome will not occur (6,18), and infants with the respiratory distress syndrome do not have phosphatidylglycerol in tracheal aspirates until the disease has resolved (16). Similar changes in surfactant phospholipid composition with development were documented in the rabbit; however, phosphatidylglycerol was not detected in the rabbit until after birth (17).…”

“…The presence of phosphatidylglycerol in amniotic fluid has been used to indicate lung maturity in the human fetus (6,18). Similarly, phosphatidylglycerol in tracheal aspirates from premature infants will exclude the possibility of the respiratory distress syndrome developing (16).…”

“…The only indication that phosphatidylinositol may be important to surfactant function is the developmental data showing a selective increase in the relative amount of phosphatidylinositol present in amniotic fluid samples and tracheal aspirates from human fetuses and newborns just before the expected appearance of phosphatidylglycerol in these biological fluids (16)(17)(18). Phosphatidylinositol increased from 3.9% of lung to 7.5% of alveolar wash fraction phospholipids in these 3-day-old rabbits, possibly indicating a preferential secretion of phosphatidylinositol, as the relative concentration of the phospholipid in alveolar wash was higher than the 5.2% measured in the adult rabbit (25).…”

Effect of blood and meconium on the determination of phospholipids in amniotic fluid using high pressure liquid chromatography

“…Most important determinations include the L/S ratio [7], the quantitative determination of lecithin (phosphatidylcholine PC) by thin layer chromatography [13] and by enzymatic determination [5,12]. Other phospholipids have also been detected by two-dimensional thin layer chromatography and the presence and relative concentration of phosphatidylglycerol (PG) and phosphatidylinositol (PI) have been reported to be indicators of fetal lung maturity [3,9]. Clinically used methods which measure only lecithin or the L/S ratio as well as unspecific tests such as the shake test [4] or the determination of the optical density at 650 nm [14] are not reliable in cases of contamination of the amniotic fluid by blood and meconium [2,5,10,11].…”