Application of a new perchloric acid treatment method to measure endotoxin in both amniotic fluid and cord blood by an endotoxin-specific chromogenic Limulus test in intra-amniotic infection.

Endotoxin in both amniotic fluid and cord blood was measured to detect intra-amniotic fetal infection. Both amniotic fluid and cord blood plasma were pretreated by a perchloric acid treatment, and the endotoxin level was measured by Endospecy test. Cut off values for endotoxin in amniotic fluid and cord blood were 8.5 pg/mL and 7.6 pg/mL, respectively. Escherichia coli intra-amniotic infection caused respiratory distress syndrome (RDS)-mimicking pneumonia. Abnormally high values of endotoxin in both amniotic fluid and cord blood were detected. Intra-amniotic infection caused by Gram-positive bacteria (group B streptococci, Enterococcus fecalis) was shown to be endotoxin negative in both amniotic fluid and cord blood. In cases of negative amniotic fluid culture, measurement of the value of endotoxin in the amniotic fluid is useful in identifying intra-amniotic fetal infection.