[Surfactants in amniotic fluids: a comparision between biomechanical and biochemical analyses (author's transl)].

44 specimens of amniotic fluid from the 25 week's gestation onwards were tested in a modified Wilhelmy-Langmuir surface balance. In addition percentage of lecithin in total phospholipids, total phospholipd phosphorus concentration and fatty acid composition of lecithin was determined. Lecithin, total phospholipid-phosphorus and palmitic acid show significant rises in concentration with gestational progress. The results of the surface tension measurements are significantly correlated with the biochemical analysis. Therefore, fetal lung maturity seems to be well estimated by the biomechanical method.