Relationship between Cervical Mucus Interleukin‐8 Concentrations and Vaginal Bacteria in Pregnancy

Abstract
Problem:  High interleukin (IL)‐8 concentration in cervical mucus in the second trimester is a risk factor for premature birth. We investigated the relationship between vaginal pathogens and IL‐8 in cervical mucus.Method of study:  In 501 women with single pregnancy, vaginal secretions were cultured for bacteria and cervical mucus IL‐8 concentrations were measured between 20 and 24 gestational weeks.Results:  Lactobacillus species were detected in 56.0% of 84 subjects with high IL‐8 (≥377 ng/mL), significantly less often than in 417 subjects with IL‐8 below 377 ng/mL (84.7%; P < 0.0001). Anaerobic pathogens were detected in 83.3% of high IL‐8 subjects, significantly more often than in normal IL‐8 subjects (43.9%; P < 0.0001). By multivariate analysis, cervical IL‐8 was significantly high only in subjects without Lactobacillus species; they showed a significantly higher prematurity rate than Lactobacillus‐positive subjects.Conclusions:  Absence of vaginal Lactobacilli was associated with increased cervical IL‐8 and increased risk of premature delivery.