Role of isosorbide mononitrate in induction of labour: A single arm clinical trial at a tertiary care hospital
Keywords:Isosorbide mononitrate, cervical ripening, induction of labour, Bishop score
Introduction and Aim:Isosorbide mononitrate, a nitric oxide donor, induces the enzyme cyclo-oxygenase-2, leading to production of local prostaglandins in human cervix and leads to structural rearrangement of the collagen network and thereby the cervix ripens.The aim of this study was to determine the role of Isosorbide mononitrate in induction of labour, determine induction delivery interval and obstetric and neonatal outcome.
Materials and Methods:This study was an interventional study on 40 pregnant women conducted for a period of one year. Women requiring induction of labour, who met the inclusion criteria, were enrolled. Isosorbide mononitrate (40 milligrams) was inserted in the posterior fornix. If Bishop's score did not change after 24 hours of the initial dose, failure of induction of labour was considered.Those patients in whom labour pains started after isosorbide mononitrate alone were considered to be in successful group(A) while those who required additional drugs like prostaglandins were considered to be in the failed group(F).
Results:The mean (SD) Bishop score after 1dose of isosorbide mononitrate in the successful group (A) was 6.04 (2.16) and in the failed group (F) was 3.81 (0.83). There was a significant difference in terms of Bishop Score after 1st Dose of IMN (W = 310.000, p = 0.001) and in terms of induction-delivery time in hours (t = -2.386, p = 0.023).
Conclusion:This study concludes that Isosorbide mononitrate has significant role for induction of labor in terms of Bishop score changes and induction delivery interval.
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