foam sta·bil·i·ty test
a test for fetal pulmonary maturity, determined by the ability of pulmonary surfactant in amniotic fluid to generate stable foam in the presence of ethanol after mechanical agitation.
Synonym(s): shake test
a qualitative test for fetal lung maturity. It is more rapid than determination of the lecithin/sphingomyelin ratio. Also called foam test.
shake testFoam stability index, see there.
A quick test to estimate fetal lung maturity. A sample of amniotic fluid is diluted with normal saline, mixed with 95% ethyl alcohol, and shaken for 30 sec. The continued presence of small foamy bubbles in the solution after 15 min confirms the presence of pulmonary surfactant.Synonym: foam stability test; rapid surfactant test