Vaginal fluid IL-6 and IL-8 levels in pregnancies complicated by preterm prelabor membrane ruptures.

Objective: To determine the vaginal fluid interleukin (IL)-6 and IL-8 concentrations in pregnancies complicated by preterm prelabor rupture of membranes and their correlation to microbial invasion of the amniotic cavity (MIAC) as well as histological chorioamnionitis (HCA).

Methods: Sixty-eight women with singleton pregnancies were included in this study. Vaginal fluid was collected at the time of admission. IL-6 and IL-8 concentrations in the vaginal fluid were determined using ELISA.

Result: Women with MIAC had higher vaginal fluid IL-6 levels compared to those without MIAC (with MIAC: median 374 pg/mL versus without MIAC: median 174 pg/mL; p = 0.03). IL-8 levels were higher in women with MIAC only in the crude analysis but not after adjustment for gestational age. There was no difference in the IL-6 and IL-8 concentrations between those with and without HCA. Women with both MIAC and HCA had higher IL-6 vaginal fluid levels than those without both MIAC and HCA (with MIAC and HCA: median 466 pg/mL versus without MIAC and HCA: median 178 pg/mL; p = 0.02). IL-8 levels were higher in women with MIAC and HCA only in the crude analysis but not after adjustment for gestational age.

Conclusions: Vaginal fluid IL-6 but not IL-8 levels reflect the presence of MIAC and both MIAC and HCA.