Increasing evidence suggests that parturition is an inflammatory process. In this brief overview, inflammatory events occurring in association with parturition, and the mechanism by which they may contribute to labour and delivery will be discussed. Mention will be made of how this information may be of use in regulating the timing and the onset of parturition.

Objective To determine whether isosorbide mononitrate (IMN), self-administered vaginally by women at home, improves the process of induction of labour.Design Randomised double blind placebo-controlled trial.Setting Large UK maternity hospital.Population or Sample Nulliparous women with a singleton pregnancy, cephalic presentation ‡37 weeks gestation, requiring cervical ripening prior to induction of labour.Methods IMN (n = 177) or placebo (n = 173) self-administered vaginally at home at 48, 32 and 16 hours prior to the scheduled time of admission for induction.Main outcome measures Admission to delivery interval and women's experience of induction of labour.Results IMN did not shorten the admission to delivery interval as compared with placebo [mean difference of )1.6 hours (95% CI )5.1,1.9, P = 0.37)], despite being more effective than placebo in inducing a change in Bishop score [mean difference of 0.65 (95% CI 0.14,1.17, P = 0.013)]. While both groups found the overall experience of home treatment to be positive, (mean score of 3.8/ 10 ± 2.3/10 for the IMN group, where 1 = extremely good and 10 = not at all good) women in the placebo group found it marginally more positive than those in the IMN group (just over half a unit on a 10-point scale, P = 0.043). There were no differences between the groups in the pain or anxiety experienced or willingness to take the treatment in a subsequent pregnancy.Conclusions IMN self-administered vaginally at home does not shorten admission to delivery interval despite a significant effect on cervical ripeness assessed using the Bishop score. However, women report positive views on cervical ripening at home, and the setting deserves further investigation.

Toll-like receptors 2and 4 and TREM-1 are expressed in human myometrium and may play a role in the mechanism of labor at term, and their functional effects are inhibited by MPA.