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 mu g, 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. (C) 2005 Elsevier Inc. All rights reserved.