Value of amniotic fluid interleukin-8 for the prediction of histological chorioamnionitis in preterm premature rupture of membranes.

Objective: To determine whether amniotic fluid levels of interleukin-8 (IL-8) are of value in the antenatal diagnosis of acute histological chorioamnionitis (HCA) in preterm premature rupture of membranes (PPROM).

Setting: Department of Obstetrics and Gynaecology, Charles University, Medical School and University Hradec Kralove, Czech Republic.

Methods: We compared amniotic fluid IL-8 levels in twenty-nine pregnant women with preterm premature rupture of membranes between 24th and 36th gestational weeks with presence and absence acute histological chorioamnionitis or/and microbial invasion in the amniotic cavity using nonparametric tests (Mann-Whitney test), given the non-normal distribution of analyte. Comparisons of proportions were performed with Shapiro-Wilk normality test.

Results: Patients with HCA had a significantly higher median amniotic fluid IL-8 concentration than patients without the histological signs of chorioamnionitis (1867 pg/mL, 826-5577 versus 1045 pg/mL, 60-4133, p=0.013). Patients with MIAC had a significantly higher median amniotic fluid level than patients without invasion (1888 pg/mL, 519-5577 versus 1225 pg/mL, 60-2766, p= 0.017). Women with HCA and MIAC had a significantly higher median amniotic fluid IL-8 level than women without histological signs of chorioamnionitis and microbial invasion (3117 pg/mL, 826-5577 versus 1468 pg/mL, 394-2766, p=0.034).

Conclusions: HCA or/and MIAC are associated with a significant increase of amniotic fluid interleukin-8 levels. Amniotic fluid IL-8 seems to be a marker of intraamniotic inflammation.