Objective: To compare the diagnostic value of intercellular adhesion molecule (ICAM)-1 with that of C-reactive protein (CRP) and white blood cell (WBC) count for detecting histologic chorioamnionitis in serum of women with preterm labor.
Methods: Maternal blood was collected from 97 consecutive women admitted with preterm delivery before 37 weeks' gestation, and 50 women after normal term delivery (38-41 weeks' gestation). Intercellular adhesion molecule-1, CRP, and WBC count were measured before delivery.
Results: Histologic chorioamnionitis was diagnosed in 48 of 97 women (48%) who delivered preterm and in none who delivered at term. Maternal serum levels of ICAM-1 (median 169 ng/mL, range 94-510 ng/mL, P <.001), CRP (median 2.8 ng/mL, range 0.5-13.2 mg/dL, P <.001) and WBC count (12.6 x 10(3)/microL, range 6.4-30.6 x 10(3)/microL, P <.02) were statistically significantly higher in women with histologic chorioamnionitis than those without it (ICAM-1 median 70 ng/mL, range 23-107 ng/mL; CRP median 0.7 mg/dL, range 0.5-6.7 mg/dL; WBC count median 10.9 x 10(3)/microL, range 4.3-22.2 x 10(3)/microL). The sensitivity and specificity of maternal serum ICAM-1 (cutoff 106 ng/mL), CRP (cutoff 1.1 mg/dL), and WBC count (cutoff 11.8 x 10(3)/microL) for diagnosing histologic chorioamnionitis were 98.0% and 93.8%, 75.5% and 71.4%, and 63.3% and 61.2%, respectively.
Conclusion: In women with preterm labor, ICAM-1 is a more reliable indicator of histologic chorioamnionitis than CRP or WBC count.