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/mL] 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 (CI), 1.8 to 50.3]). Women with preterm delivery had suggestively higher amniotic fluid concentrations of cortisol (mean 1.3 [SE 0.2] microg/dL [range, 0.4 to 2.2 microg/dL]) than women delivering at term (mean 1.0 [SE 0.09] microg/dL [range, 0.6 to 1.7 microg/dL], P < .07). Furthermore, cortisol levels were positively correlated with ADAM-8 levels (Spearman's r = .418, P < .014).

Conclusions: Elevated mid-trimester amniotic fluid ADAM-8 concentrations possibly are a risk factor 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.