Publication:

A comparative study of safety and efficacy of vaginal isosorbide mononitrate (40mg) with dinoprostone gel (0.5mg)

Background It is essential to intervene pregnancy for safety of mother, fetus or both. Successful labor induction is clearly related to the state of the cervix. Women with an unfavorable cervix who have not experienced cervical ripening phase before labor present the greatest challenge with regard to labor induction. Therefore, it is necessary to use optimal technique for cervical ripening and safe confinement. One of the common methods includes use of PGE2 gel for cervical ripening. The rationale of this study is to compare the safety and efficacy of Iso-sorbide mononitrate as pre-induction cervical ripening with PGE2 gel induction.

Methods After attaining ethics approval [PSG IHEC], a prospective randomised, case-controlled study was conducted on 182 women undergoing elective induction of labour. They were allocated to either Study or Control group by computer generated random number table method. ISMN was used vaginally prior to labour induction in the study group whereas PGE2 gel induction was used in the control group. Change in bishop score and Induction to delivery interval was assessed in both the groups.

Results There was a significant reduction in induction to delivery interval in the study group (ISMN) 15.2 hours when compared to 23.2 hours in the control group (PGE2 gel) with p=0.000. Need for augmentation of labour was reduced in the study group significantly with p=0.003. Cost of induction was less when compared to the control group. ISMN had less side effects hence can be used as OP basis.

Conclusions Vaginal Isosorbide mononitrate when used as a cervical ripening agent significantly reduces induction to delivery interval. Use of Isosorbide mononitrate was associated with very less side effects and it is a cost-effective drug. Thus, ISMN can be used safely and effectively in term patients for pre-induction cervical ripening when compared to PGE2 gel.