RDS and tracheal phospholipid composition in twins: independent of gestational age.

The surfactant phospholipids in the tracheal effluent of eight pairs of preterm twins were followed, serially. In four pairs only one of the twins had RDS; in the other four pairs both twins had RDS. Twins with and without RDS had markedly different surfactant phospholipids. Phosphatidylglycerol was absent in all twins with RDS. L/S ratios in tracheal effluent increased after birth in infants with and without RDS. With recovery from RDS, phosphatidylinositol increased. The study helps confirm previous studies of the necessity of the acidic phospholipids, PI and PG, in stabilizing lecithin, as well as that surfactant composition can be independent of gestational age.