Related Experiment Videos
Phospholipids and creatinine in amniotic fluid in relation to gestational age
185 samples of amniotic fluid were obtained from 174 healthy women with uncomplicated pregnancies in the 15th-43rd week of pregnancy by abdominal amniocentesis or by puncture of the amniotic sac via an amnioscope. The concentrations of creatinine (183 cases), phospholipid phosphorus and the ratio of lecithin/sphingomyelin (L/S-ratio, 130 cases) were determined. The treatment of the amniotic fluid samples (centrifugation, filtration and lipid extraction) and the methods for the determination of L/S-ratio were examined and the accuracy and limitations of the latter method were defined and discussed. The relative amounts of lecithin and sphingomyelin as well as the L/S-ratio and creatinine concentration were closely correlated to gestational age. A L/S-ratio of greater than or equal to 2.25 indicated all women to be greater than or equal to 34th week of pregnancy; 64% of them had reached the 38th week. A creatinine concentration of greater than or equal to 1.8 mg% corresponded to X greater than or equal to 35th week or pregnancy, while 75% of the women had reached at least the 38th week. With a L/S-ratio greater than or equal to 2.25 and a creatinine concentration greater or equal to 1.8 mg% of all women were greater than or equal the 36th week. 71% of the women greater or equal the 38th week fulfilled these critiera. A combination of the two parameters seems to be of a great value in discrimination between gestational ages less than the 36th week and greater than or equal to the 38th week.
185 samples of amniotic fluid were obtained from 174 healthy women with uncomplicated pregnancies in the 15th-43rd week of pregnancy by abdominal amniocentesis or by puncture of the amniotic sac via an amnioscope. The concentrations of creatinine (183 cases), phospholipid phosphorus and the ratio of lecithin/sphingomyelin (L/S-ratio, 130 cases) were determined. The treatment of the amniotic fluid samples (centrifugation, filtration and lipid extraction) and the methods for the determination of L/S-ratio were examined and the accuracy and limitations of the latter method were defined and discussed. The relative amounts of lecithin and sphingomyelin as well as the L/S-ratio and creatinine concentration were closely correlated to gestational age. A L/S-ratio of greater than or equal to 2.25 indicated all women to be greater than or equal to 34th week of pregnancy; 64% of them had reached the 38th week. A creatinine concentration of greater than or equal to 1.8 mg% corresponded to X greater than or equal to 35th week or pregnancy, while 75% of the women had reached at least the 38th week. With a L/S-ratio greater than or equal to 2.25 and a creatinine concentration greater or equal to 1.8 mg% of all women were greater than or equal the 36th week. 71% of the women greater or equal the 38th week fulfilled these critiera. A combination of the two parameters seems to be of a great value in discrimination between gestational ages less than the 36th week and greater than or equal to the 38th week.