[Secretory immunoglobulin A (S-IgA) in amniotic fluid and in pharyngeal mucus and urine of newborn infants].

S-IgA was estimated in amniotic fluid and in mucus samples of pharyngeal cavities and urine samples of newborns for assistance of the hypothesis that there is a connection between S-IgA content in amniotic fluid and fetal pulmonary maturity. It was used an antiserum against human secretory component and an S-IgA standard in the single radial immunodiffusion according to Mancini and coworkers. High S-IgA concentrations in the mucus samples of pharyngeal cavities refer to fetal bronchial-pulmonary system as the probable essential part in the synthesis of S-IgA established in amniotic fluid of the 3rd trimenon in pregnancy.