Randomized comparison of glycerol trinitrate and misoprostol for cervical ripening at term

ABSTRACT

The study was undertaken to assess efficacy and adverse effects of glycerol trinitrate compared with misoprostol for cervical ripening at term. The study was conducted on sixty term pregnant females with unfavorable cervices, Bishop score < 6, referred for induction of labor. They were randomly assigned, and divided into 2 groups Group [A] Includes thirty cases where Misoprostol [Cytotec] 200 micro g/tablets will be used vaginally, 50 micro g/6 hours maximally. Group [B] includes thirty cases where Nitroglycerine [Dinitra 5 mg] tablets/ 6 hours, vaginally, two doses maximally. Women were sent to the labor ward for amniotomy or oxytocin, if their Bishop scores improved more than 6 or their cervices were not ripe 24 hours after treatment, then the adverse effects, changes in Bishop scores, progress and outcome of labor were assessed. This study indicated that there was no significant difference as regards Bishop score in between both groups, but the median of Bishop scores 12 hours after PGE[1] analogue [Misoprostol] was higher than glycerol trinitrate. PGE[1] analogue [Misoprostol] group A had shorter mean duration from the start of medication till the start of pain than glycerol trinitrate [group B], the mean was 12.33, 12.12 hours respectively. Also, the time elapsed from induction till delivery was also significant in this group. P=0.001. There was highly significant tachysystole in group A, while headache, dizziness and palpitations were seen only in group B.10%, 10%, 13.3% of cases respectively, low Apgar score after 1 minute was significantly evident in group A compared to group B. Glycerol trinitrate is less effective than PGE[1] analogues [misoprostol] for ripening at term. It causes less tachysystole than misoprostol but headache, dizziness, palpitation are more in glycerol trinitrate group. Further study is needed to determine optimal dose and effectiveness of glycerol trinitrate for cervical ripening