[Studies on surface tension of amniotic fluid with special emphasis on evaluating fetal lung maturity].
In order to establish a simple and rapid test for the determination of fetal lung maturity, surface tension (ST) of lipid extracts prepared from amniotic fluid samples obtained from 54 women was measured by Wilhelmy's method. The patterns of ST were classified into three types. Type I: ST of 45 dyne/cm or more at 200 microliters of extract and 36 dyne/cm or more at 350 microliters. Type II: ST of 45 dyne/cm or more at 200 microliters and less than 36 dyne/cm at 350 microliters. Type III: ST less than 45 dyne/cm at 200 microliters. L/S ratio was 2 or more (greater than or equal to 2) in 7 of 23 cases (30.4%) with Type I patterns, 2 of 6 cases (33.3%) with Type II patterns, and 24 of 25 cases (96.0%) with Type III patterns. ST of mature amniotic fluid centrifuged for 10 min. at 5,000 X g and 10,000 X g was higher than ST of mature amniotic fluid centrifuged at 450 X g and 1,000 X g, but ST of immature amniotic fluid showed no significant difference in ST at different centrifugal forces. Contamination with meconium and blood was found to lower ST of immature amniotic fluid remarkably. ST of amniotic fluid lipid extract appeared to be a simple, rapid and reliable method for the assessment of fetal lung maturity.
Kashiwabara
Y
Y
Maeda
H
H
Yamaguchi
Y
Y
Shimokawa
H
H
Hisanaga
S
S
Nakano
H
H
D000653:Amniotic Fluid / Q000032:analysis* / Q000502:physiology; D001769:Blood; D002498:Centrifugation; D005260:Female; D005325:Fetal Organ Maturity; D005865:Gestational Age; D006801:Humans; D008168:Lung / Q000196:embryology*; D008470:Meconium / Q000032:analysis; D010713:Phosphatidylcholines / Q000032:analysis; D011247:Pregnancy; D013109:Sphingomyelins / Q000032:analysis; D013500:Surface Tension
D010713:Phosphatidylcholines; D013109:Sphingomyelins