The temperature effect on the threshold dilution (e.g., threshold concentration) for formation of foam bilayers (Newton black films) from amniotic fluid is investigated. Samples of amniotic fluid are collected during the 39th gestation week. Microscopic foam films are formed from diluted amniotic fluid and studied interferometrically by the method of Scheludko and Exerowa within the temperature range 10-30 degrees C. The threshold dilution is determined from the experimental dependence of the probability for observation of foam bilayer on the dilution for each sample at different temperatures. It is shown that the threshold dilution is inversely proportional to the threshold concentration for formation of foam bilayer. This parameter is crucial for assessment of the risk for respiratory distress syndrome in newborns. The binding energy Q of a lipid molecule in the foam bilayer is calculated from the Arrhenius dependence of the threshold dilution applying the hole-nucleation theory of bilayer stability. The so-obtained values of Q for the various samples are very close to each other and vary from 5.3 x 10(-20) to 9.4 x 10(-20) J (about 13-22 kT), which indicates that in all cases the foam bilayers are in the liquid-crystalline state. Comparison is made with the phase states of dipalmitoylphosphatidylcholine foam bilayers.