Association between funisitis and elevated interleukin-6 in cord blood

Objective: To determine whether elevated plasma interleukin-6 (IL-6) in umb ilical venous cord blood at delivery is associated with funisitis and wheth er IL-6 can be used to screen for funisitis in preterm neonates. Methods: At the time of delivery, umbilical venous cord blood samples were collected from 92 infants for whom placental pathology results were also av ailable. Interleukin-6 concentrations in the umbilical venous cord blood pl asma were measured by immunoassay. Histologic examinations of the placenta and umbilical cord were done to determine the presence or absence of funisi tis and chorioamnionitis. For a power of 90% with an alpha of .05, 12 subje cts were required in each group. Results: We found a significant association between the presence of histolo gic funisitis and elevated umbilical venous cord blood plasma IL-6 concentr ations (defined as 10 pg/mL or greater). Of 15 infants whose umbilical cord s showed funisitis, 93% (14 of 15) had elevated umbilical venous cord blood plasma IL-6 concentrations. Of 77 infants without funisitis, 32% (25 of 77 ) had elevated IL-6 concentrations in their cords (P < .001, two-sided Fish er exact test). The negative predictive value of IL-6 as a screening test f or funisitis was 98%. Conclusion: In preterm neonates, screening for funisitis by using the immun oassay for IL-6 appears to be valid. In the near future, elevated umbilical venous cord blood IL-6 concentrations at delivery could be clinically usef ul to identify children who might benefit from early treatment for systemic fetal inflammatory syndrome. (Obstet Gynecol 2001;97:220-4. (C) 2001 by Th e American College of Obstetricians and Gynecologists.).