|Year : 2014 | Volume
| Issue : 2 | Page : 73-76
Randomized prospective trial to compare the efficacy and safety of intra-vaginal misoprostol with intra-cervical dinoprostone gel in induction of labor
Wanker Nongkhlaw, Ch Manglem Singh, Shongkunlang Sing Phanbuh, Annapurna Acharya, Vanlalremsanga Varte, Ningthoukhongjam Romita Devi
Department of Ostetrics and Gynaecology, Regional Institute of Medical Sciences, Imphal, Manipur, India
|Date of Web Publication||18-Sep-2014|
Dr. Vanlalremsanga Varte
104, Mission Veng Bazar, Aizawl - 796 005, Mizoram
Source of Support: None, Conflict of Interest: None
Induction of labor is the intentional or artificial initiation of labor before spontaneous onset of labor. At present dinoprostone is the agent of choice but misoprostol is a potential alternative. Objectives: To compare the efficacy and safety of intravaginal misoprostol with intracervical dinoprostone in induction of labor. Materials and Methods: Two groups of 135 subjects received 0.5 mg of dinoprostone gel intracervically and tab misoprostol 25 μg digitally placed at the posterior fornix. Results: In group-one (Dinoprostone gel), 116 (85.9%) had vaginal delivery, 13 (9.6%) had ventouse delivery and six (4.4%) underwent cesarean section, whereas in group-two (Misoprostol), 118 (87.0%) and 12 (8.9%) had vaginal and ventouse delivery respectively, whereas 5 (3.7%) underwent cesarean section. Induction to delivery interval was less than 12 hours in 50% when induced with misoprostol and 33.3% with dinoprostone. Median Bishop score at the time of instillation was found to be 3 (Range 2-4) while equivalent median Bishop score for the latter group is 2 (Range 2-4) in group-one and two respectively. The difference observed was significant (P = 0.026) indicating that misoprostol improves the Bishop score more significantly than dinoprostone. No significant variation in Apgar score and maternal complications was noted in both groups. Conclusion: Both dinoprostone and misoprostol are effective agents for induction. Misoprostol with its shorter induction delivery interval, cheaper cost and less stringent storage conditions may be preferred in developing countries.
Keywords: Misoprostol, Dinoprostone, Labour induction
|How to cite this article:|
Nongkhlaw W, Singh C, Phanbuh SS, Acharya A, Varte V, Devi NR. Randomized prospective trial to compare the efficacy and safety of intra-vaginal misoprostol with intra-cervical dinoprostone gel in induction of labor. J Med Soc 2014;28:73-6
|How to cite this URL:|
Nongkhlaw W, Singh C, Phanbuh SS, Acharya A, Varte V, Devi NR. Randomized prospective trial to compare the efficacy and safety of intra-vaginal misoprostol with intra-cervical dinoprostone gel in induction of labor. J Med Soc [serial online] 2014 [cited 2021 May 11];28:73-6. Available from: https://www.jmedsoc.org/text.asp?2014/28/2/73/141079
| Introduction|| |
Induction of labor is the intentional or artificial initiation of labor before spontaneous onset for the purpose of delivery of the feto-placental unit. Rate of induction at term varies in different centre and is approximately 20% of all deliveries.  Labor induction in the presence of an unfavorable cervix may be prolonged, tedious and eventuate in failed induction, hence cesarean delivery. Cervical ripening with prostaglandin agents decreases induction and need for oxytocin.  The use of prostaglandins for cervical ripening turns out to have a positive effect on spontaneous vaginal delivery rate and thus women are less likely to require a cesarean section.  They alter the extracellular ground substance of the cervix and prostaglandin E2 (PGE-2) increases the activity of collagenase in the cervix. Finally prostaglandin allows for an increase in intracellular calcium level, causing contraction of myometrial muscle.  At present dinoprostone is the agent of choice for inducing labor, but this is a relatively expensive drug and requires refrigeration for storage. Misoprostol is a potential alternative. It is a PGE1 analogue that is stable at room temperature, easy to administer and of lower cost.
Aims and Objects
To compare the efficacy and safety of intravaginal misoprostol with intracervical dinoprostone in induction of labour.
| Materials and Methods|| |
A prospective, observational, interventional and analytical study was conducted in the department of Obstetrics and Gynaecology, Regional Institute of Medical Sciences (RIMS), Imphal after obtaining approval from the institutional ethics committee. A total of 270 patients admitted to labor room with singleton, term, post-dated or post-term pregnancy with vertex presentation were recruited.
- 135 subjects in Group-one received 0.5 mg of dinoprostone (PGE-2) gel intra cervically through an inert gel applicator and 135 subjects in group-two received 25 ug of tablet misoprostol placed digitally in the posterior fornix of the vagina. The patients were advised to remain in recumbent position for 30 minutes in both groups after administration of the drugs.
- PGE-2 gel 0.5 mg was repeated at least 6 hours apart for a maximum of 3 doses when required. Tab. misoprostol 25 μg was repeated at least 4 hours apart for a maximum of 3 doses and monitored half hourly for uterine contraction, fetal heart rate and maternal vital signs. Cervical changes was assessed by pelvic examination after 6 hours after induction. Partogram was plotted for progress of labor.
- All women were studied for demographic profile, gestational age, induction delivery interval, mode of delivery, indication for operative interference, fetal distress, failed induction, uterine tachysystole, hyperpyrexia and fetal outcome which were then recorded in a proforma. Fetal outcome was measured in terms of admission to neonatal care unit, the occurrence of any maternal complication were also duly noted.
Statistical analysis of data was performed by SPSS software. For categorical (qualitative) data, frequency and percentage were calculated. For quantitative data, median and range were calculated and Mann-Whitney U-test Z-value (as non-parametric test) was applied to test the difference of medians.
| Results and Observations|| |
Maximum number of women were of 20-30 years of age, 103 (76.3%) subjects in group-one and 83 (61.48%) in group-2. Majority of the subjects were nulliparous (P0 + 0 or P0 + 1), 78 (57.78%) in group-one and 84 (62.22%) in group-two [Table 1]. Most common indication for induction of labor was term gestation, 83 (61.5%) and 92 (68%) in group-one and two respectively. Others indications were postdated pregnancy, term gestation with pre-eclampsia, pre-labor rupture of membranes and post-term pregnancy in the decreasing order. The nature of indication of induction in both the groups is almost similar, however were not significant (P = 0.732). In group-one, 116 (85.9%) had vaginal delivery, 13 (9.6%) had ventouse delivery and 6 (4.4%) underwent cesarean section, whereas in group-two, 118 (87.0%) and 12 (8.9%) had vaginal and ventouse delivery respectively and 5 (3.7%) underwent cesarean section. Of the eleven 11 subjects who had caesarean, cervical dystocia was indicated in 4 (2.9%) and 3 (2.2%) cases. Fetal distress was indicated in 2 (1.4%) cases each of both groups. The induction to delivery interval was more than 12 hours in 84 (62.2%) and 62 (42%); and was less than 12 hours in 45 (33.3%) and 68 (50%) in group one and two respectively. This observation was statistically significant (P = 0.018) [Table 2]. No significant variation of Apgar scores were noticed in either groups (P = 0.259) [Figure 1]. Safety of the drugs for induction were assessed by recording the occurrence of maternal complications like atonic and traumatic postpartum hemorrhage (PPH) and fetal complications like fetal distress and birth asphyxia. Atonic and traumatic PPH occurred in 4 (2.9%) and 8 (2.9%) cases each in group-one and two respectively and was statistically insignificant (P = 1.000). Fetal complication was seen in 10 (7.4%; birth asphyxia) and 5 (3.7%; fetal distress) group-one and in 12 (8.9%; birth asphyxia) and 6 (4.4%; fetal distress) in group-two and was not found significant [Table 3]. Median Bishop score at the time of instillation was found to be 3 (Range 2-4) while equivalent median Bishop score for the latter group is 2 (Range 2-4) in group-one and two respectively. The difference observed was significant (P = 0.026) indicating that misoprostol improves the Bishop score more significantly than dinoprostone.
|Table 2: Showing the mode of delivery, indication for caesarean and the induction delivery interval (IDI) in either groups of the study|
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|Table 3: Showing occurrence of maternal and fetal complications in the study groups|
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| Discussion|| |
Age of the patient did not have a direct relationship with the success of induction. In the study majority of the subjects were in the age group of 20-30 years and nullipara constituted about 60.04% of the total study population. The study showed that term pregnancies (64.8%) comprises the maximum number of patient undergoing induction followed by post-dated pregnancies (22.2%), PET (6.67%) and premature rupture of membranes (PROM) (5.56%). However this was found not to be of any statistical difference and is in accordance to a study conducted by Rozenberg et al. 
Lapaire O et al.,  observed that more cesarean section was done in the dinoprostone group due to failed induction. In this regard, our study showed that there was no statistical difference in the mode of delivery. The success of induction in terms of vaginal delivery, occurred in 85.9% and 87% cases of group-one and two respectively and the results were comparable with Gregson S et al.,  study Instrumental delivery is seen in 4.4% and 9.6% in the dinoprostone group and in 3.7% and 8.9% in the misoprostol group. However the observed difference was found not to be of any significant (P = 0.929). A study conducted by Calder AA et al.,  observed that the induction to delivery interval (delivery occurring within 12 or > 12 hour of induction) does not significantly differ between the misoprostol and dinoprostone (43 versus 47%, 3.74% difference, 95% CI-3.58-11.05, respectively) groups. However in the study we found that the induction to delivery interval was shorter in those who received misoprostol than dinoprostone. Bishop score was calculated for each patient before induction, the median bishop score at the time of induction in the dinoprostone group is found to be 3 with a range of 2-4, while the median Bishop score in the misoprostol group is 2 with the range of 2-4. Nevertheless the difference observed is still significant (P = 0.026), indicating that misoprostol improves the Bishop score more significantly than does dinoprostone. This is in accordance to a study conducted by Wasim T et al. 
No variation in the Apgar score is noticed between the two groups, recording a score of > 7 in 90.4% and 86.0% of babies born after induction with dinoprostone and misoprostol group respectively which was in accord with the reports of Rozenberg R et al.,  and Langenegger et al. 
The present study showed that the maternal and foetal complications were comparable in both groups. Maternal complications such as atonic PPH occurred in 2.9% and 3% and traumatic PPH in 2.9%% and 3% of subjects in the dinoprostone and misoprostol group respectively. However this observed difference was not found to be statistically different (P = 1.000). The perinatal complication like fetal distress was seen in 3.7% and 4.4% in the dinoprostone and misoprostol group respectively. Birth asphyxia was seen in 7.4% and 8.9% in the dinoprostone and misoprostol group respectively. But the variation is insignificant at 5% probability level statistically (P = 0.498).These observations were in accordance to studies conducted by Calder AA et al.,  and Prager M et al. 
| Conclusion|| |
Success of induction measured in terms of occurrence of vaginal delivery was 86.7% among the study subjects and was comparable in both the groups. Cesarean section was done only in 4% of the subjects for either cervical dystocia or fetal distress. The induction to delivery interval was less than 12 hours in 50% of the patients induced with misoprostol when compared with 33.3% in those induced with dinoprostone. These values were statistically significant concluding that misoprostol was efficacious when compared to dinoprostone. No significant variation was seen in Apgar score or maternal complications in either groups.
Thus intracervical dinoprostone and intravaginal misoprostol are safe, simple and convenient with less discomfort to the patients as they can be ambulant with proper monitoring of both the maternal and foetal condition. Both are effective for induction of labour but the induction delivery interval was shorter in the misoprostol group. Apgar score was similar in both the groups. However misoprostol is relatively cheap, requires less stringent condition for storage and is equally effective and safe in inducing labor at term. As such it may be preferred as the agent of choice in the induction of labor especially in a developing country like our, allowing considerable cost saving.
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[Table 1], [Table 2], [Table 3]