The effect of orally and vaginally administered misoprostol on inflammatory mediators and cervical ripening during early pregnancy.

OBJECTIVES

The objective of the present study was to investigate the effect of vaginally and orally administered misoprostol on the local cervical inflammatory response.

METHODS

Healthy women with a normal intrauterine pregnancy between 8 and 12 weeks of gestation presenting for an elective termination of pregnancy by vacuum aspiration were recruited into a cohort study with a control and a treatment group. In the treatment group, the women were randomized to misoprostol, 400 mug, given either orally or vaginally 3 h before surgery. Immunohistochemistry staining of CD45, CD68, MMP 8, MMP 9, TIMP 1 and TIMP 2 were assessed in cervical biopsies obtained directly prior to mechanical cervical dilatation and vacuum aspiration.

RESULTS

In the treatment group, there was a greater amount of CD45-positive cells in the subepithelium region of the cervix compared to the control group. The staining of CD68 was similar in both groups. The immunostaining of MMP 8 and MMP 9 was greater in the treatment group, while the expression of TIMP 1 and TIMP 2 did not differ between control and treatment groups.

CONCLUSIONS

Compared to untreated controls, treatment with misoprostol was associated with a greater expression of inflammatory cells. It could be hypothesized that administration of misoprostol mimics the cervical ripening at term pregnancy by a possible influx and activation of inflammatory cells, which increases MMP 8 and MMP 9 and thereby leads to the degradation of collagen and cervical softening.