The purpose of this study was to investigate the effect of vaginal
progesterone on endocervical
cytokine concentration in women at risk of
threatened abortion. One hundred and sixty pregnant women with clinical symptoms of
threatened abortion before the 20th week of pregnancy were randomly assigned to receive vaginal
progesterone or placebo. Cervical fluids were collected and endocervical concentrations of different
cytokines (IFNγ, TNFα, IL-8, IL-10 and
IL-12) were analyzed before and one week after
progesterone or placebo treatment. A significant decrease in IFNγ and increase in
IL-10 in endocervical fluid was seen when the values were compared before and after
progesterone treatment. However, there were no significant differences in pregnancy outcomes between the placebo and
progesterone groups. We conclude that despite the failure of vaginal
progesterone treatment to improve pregnancy outcomes,
progesterone can induce a shift in the concentration of
cytokines in endocervical secretions.