title: The lecithin/sphingomyelin ratio in twin pregnancies.
abstract: The lecithin/sphingomyelin ratio showed no difference between the two amniotic sacs in 24 multiple pregnancies examined before the onset of labor. Once labor started, however, the L/S ratio was higher in the first sac compared to the second in the six pregnancies where labor had commenced and was somewhat advanced at the time of amniocentesis. Dual-sac amniocentesis is essential during labor when assessment of pulmonary maturity is required, whereas single-sac sampling is adequate before the start of labor.
mesh_terms: D000653:Amniotic Fluid / Q000032:analysis*; D005260:Female; D005325:Fetal Organ Maturity; D006801:Humans; D010713:Phosphatidylcholines / Q000032:analysis*; D011247:Pregnancy; D011272:Pregnancy, Multiple; D013109:Sphingomyelins / Q000032:analysis*; D014427:Twins
chemical_list: D010713:Phosphatidylcholines; D013109:Sphingomyelins