Elevated Mid-Trimester Amniotic Fluid ADAM-8 Concentrations as a Potential Risk Factor for Preterm Delivery

Objective: To determine during mid-trimester amniocentesis if elevated concentrations of ADAM-8 (A Disintegrin And Metalloprotease 8) and/or cortisol can recognize women at risk for spontaneous preterm delivery. Methods: The study involved 312 women who underwent mid-trimester amniocentesis. Thirteen patients, who progressed to preterm delivery, were matched with 21 controls for age, parity, gestational age at amniocentesis, and year of amniocentesis. ADAM-8 and cortisol levels were measured by enzyme-linked immunosorbent assay and radioimmunoassay, respectively. Results: ADAM-8 mean amniotic fluid concentrations were significantly higher in women with preterm delivery than in women delivering at term (mean 1213.9 [SE 96.7] pg/mL [range, 780 to 1854 pg/mLJ vs mean 937.2 [SE 50.3] pg/mL [range, 486 to 1508 pg/mL], P<.02). Amniotic fluid ADAM-8 concentrations higher than 1149 pg/mL had the highest specificity and odds ratio (OR) in the identification of the women with increased risk for preterm delivery (sensitivity 61.5%; specificity 81.7%; OR, 9.6 [95% confidence interval (Cl), 1.8 to 50.3]). Women with preterm delivery had suggestively higher amnioticfiuid concentrations of cortisol (mean 1.3 [SE 0.2] µg/dL [range, 0.4 to 2.2 µg/dL]) than women delivering at term (mean 1.0 [SE 0.09] µLg/dL [range, 0.6 to 1.7 µg/dL], P<.07). Furthermore, cortisol levels were positively correlated with ADAM-8 levels (Spearman’s r=.418, P<.014). Conclusions: Elevated mid-trimester amnioticfiuid ADAM-8 concentrations possibly are a riskfactor for preterm delivery, particularly if ADAM-8 levels are greater than 1149 pg/mL. Potential intrauterine inflammation is also associated with suggestively increased amniotic fluid cortisol levels.