Evaluation of nitric acid donor, transdermal glycerol trinitrate patches for facilitating cervical ripening: a randomized controlled trial.

Abstract Purpose To evaluate the efficacy and safety of transdermal Glycerol trinitrate skin patches as an additive and effective agent for facilitating cervical ripeningMethods This was a double blinded prospective randomized clinical trial carried out in a major obstetric unit in India. Women planned for induction of labour was randomly allocated for induction of labour either by combined application of Glycerol trinitrate skin patches [GTN patch] and intracervical Dinoprostone gel or by the gel only. Sample randomization was done by using stratified block randomization technique with sealed envelope. The numbers designating the group allocation sequence were concealed from the doctors, research staff, and investigators. Six hourly improvements of the modified Bishop’s score, induction-delivery time interval, need of oxytocin, fetal outcomes and-maternal side-effects were assessed. Data were analysed by using SPSS software.Results and discussion Recruitment Bishop score, parity and gestational age were matched in both case and control group. The modified Bishop's score was statistically improved in study groups as evidenced compositely as well as irrespective of parity. There appeared no significant differences in between the two groups regarding other outcomes. Additional application of GTN patch seems helpful to accelerate the progress in Bishops score but does not affect the other labour outcomes. GTN patch does not impose any additional feto-maternal adverse effects.