Abstract
Background
Induction of labor is still a controversial obstetric procedure. The need to shorten delivery time has been recognized and practiced for centuries. Although the indications have clearly changed during the past decades from a need to expel a dead fetus to an effective solution to reduce the threat to the mother and her precious fetus, effective and safe methods of achieving delivery must always have been the primary objectives. Induction is indicated when the benefits to either mother or fetus outweigh those of pregnancy continuation. Nitric oxide donors(NO donors) such as isosorbide mononitrate could be of a great use for cervical ripening because of their effect on release of prostaglandins and vasodilation while having no or little effect on uterine activity ; since they are relatively safe and has low number of non-vital adverse effect if used with caution, they could be added to misoprostol to shorten to time needed for cervical ripening thus accelerating the whole process of induction of labor.
The Aim of this study
was to evaluate safety & efficacy of nitric oxide donors such as intravaginal isosorbide mononitrate in addition to misoprostol versus misoprostol only for the whole process of induction of labor.
Patients and Methods
in a prospective randomized double-blind placebo-controlled clinical trial which was conducted at Ain Shams Maternity University Hospital in Cairo from January 2018 to June 2018, 50 women were included in induction of labor, they were randomly divided into 2 group: Group I consisted of 25 patients, each patient was given 1 tablet of isosorbide mononitrate 40mg vaginally once and one tablet of misoprostol 25mcg vaginally; Group II consisted of 25 patients, each patient was given 1 tablet of misoprostol 25mcg vaginally. Misoprostol were given for a maximum of 5 doses (one 25mcg vaginal tablet) with interval of 6 hours between each tablet. This clinical trial was registered in clinicaltrial.gov registry with number: NCT03523754.
Results
there was a statistically significant difference between Isosorbide mononitrate & Misoprostol group versus Misoprostol only group regarding induction to delivery time ( mean 19.55 ± 1.41 to 22.94 ± 1.44 hours respectively, P-value <0.001) , induction to active phase interval (mean 10.67 ± 1.83 to 13.81 ± 0.52 hours respectively, P-value <0.001), maternal headache (36% to 12% respectively, P-value =0.047).
Conclusion
Isosorbide mononitrate appears to be a safe agent when used with misoprostol for induction of labor. It decreases induction to delivery time and induction to active phase time.
IMOP: randomised placebo controlled trial of outpatient cervical ripening with isosorbide mononitrate (IMN) prior to induction of labour – clinical trial with analyses of efficacy, cost effectiveness and acceptability
