[A study of fetal pulmonary maturity using amniotic fluid obtained from the vagina after premature rupture of membranes].

Amniotic fluid was obtained from the vagina not more than 24 hours before delivery in 100 patients who had premature rupture of the membranes. Thirty per cent of these cases had contamination with blood or with meconium. Phosphatidylglycerol (PG) estimate the degree of lung maturity using an immunological method (AMNIOSTAT-FLM test). In the 22 cases where the gestational age was 35 weeks or less there were two cases of hyaline membrane disease. In 68% of the 22 cases, the PG was negative, intermediate in 14% and positive in 18%. One of the cases of hyaline membrane disease was accompanied by fluid that was not infected and that was negative for PG; the other case had infection with S. faecalis and the PG was intermediate. On the other hand in the 78 cases when the pregnancies had lasted longer than 35 weeks there were no children who had hyaline membrane disease. The PG reaction was positive in only 57% of these cases. Search for bacteria showed infection in 10 cases (three with alpha-haemolytic streptococci, four with group B beta-haemolytic streptococci and three with E. coli). Determination of PG on the supernatant of reference strain cultures showed positive results for S. faecalis and E. coli. In conclusion, the poor specificity of the test (48%) and the possibility that when there was bacterial contamination false positive results were obtained shows that looking for fetal maturity by testing amniotic fluid from the vagina is unreliable and is contra-indicated.