Interleukin‐6 and interleukin‐8 in cervical and amniotic fluid: relationship to microbial invasion of the chorioamniotic membranes

Abstract

To evaluate the levels of interleukin (IL)-6 and IL-8 in cervical and amniotic fluid in relation to the presence of bacteria in the membranes in women in preterm labour (PTL). A prospective follow up study. Sahlgrenska University Hospital, Göteborg, Sweden. Sample Women with singleton pregnancies (<34 weeks) presenting with PTL (n = 30). Amniotic fluid was retrieved transabdominally and cervical fluid was sampled from the uterine cervix at admission and analysed for IL-6 and IL-8 with enzyme-linked immunosorbent assay (ELISA). At birth, the chorioamniotic membranes were separated and samples for polymerase chain reaction (PCR) for Ureaplasma urealyticum and Mycoplasma hominis and general culture were obtained. IL-6 and IL-8 in relation to microbial invasion of the chorioamniotic membranes. Bacteria were found in the membranes in 8 of 21 patients in PTL for whom chorioamnion as well as amniotic fluid PCR and cultures were available. Cervical IL-6 was associated with detectable bacteria in the chorioamniotic membranes in women in PTL (median 8.2 ng/mL vs 0.73 ng/mL; P = 0.01). The IL-6 (median 13 ng/mL vs 1.7 ng/mL; P = 0.004) and IL-8 (median 7.2 ng/mL vs 0.28 ng/mL; P = 0.01) levels in amniotic fluid were higher in PTL cases in which bacteria were found in the chorioamniotic membranes. IL-6 in cervical fluid and IL-6 and IL-8 in amniotic fluid were higher in those PTL cases in which bacteria were found in the chorioamniotic membranes.