Objective: The purpose was to determine the concentration of leukocyte elastase and SLPI in the cervical mucus plug, cervical tissue, fetal membranes, amniotic fluid and serum from pregnant women.
Study design: Samples were analysed using radioimmunoassay, immunodiffusion, immunohistological and enzyme assay techniques. Statistical comparisons were performed by the Mann-Whitney two-sample rank sum test.
Results: Concentrations of SLPI and elastase in cervical tissue are significantly increased during pregnancy and after delivery. Very high concentrations of SLPI and elastase were found in the cervical mucus plug. The concentrations of SLPI and elastase in human fetal membranes are highest at the rupture site. The concentration of elastase in amnion from preterm delivery was significantly higher than in amnion from term deliveries.
Conclusion: The high molar ratio of SLPI/elastase in the cervical mucus plug suggests that inhibition of elastase is important during normal pregnancy. The role of SLPI may be protection of the fetal membranes and cervical tissue.