Effect of amniotic fluid on bacterial growth.

The bacteriostatic effect of amniotic fluid was studied using four pathogenic organisms which are encountered in the perinatal period, E. coli, S. aureus, L. monocytogenes, and Group B beta hemolytic streptococci. Amniotic fluid inhibited the growth of all four organisms, with a wide degree of individual variation among specimens. The greatest degree of inhibition was noted for L. monocytogenes and the least for E. coli. The time in gestation in which the amniotic fluid sample was obtained did not appear to be related to its bacteriostatic capacity. The ability of amniotic fluid to inhibit the growth of certain pathogenic organisms may be significant in prevention of perinatal infection.