Oral and vaginal route of misoprostol for induction of labour: a comparative study

Abstract

Background: Induction of labour can be defined as “Artificial initiation of uterine contractions before the onset of spontaneous labour, after the period of viability, by any methods, for purpose of vaginal delivery.” The key factor for a successful induction is the status of cervix, its form, consistency and dilatation which is determined by the Bishop score. In case of unfavourable cervix or in the pregnancies remote from the term; prostaglandins are more effective than any other method of induction. Introduction of misoprostol, PGE1 analogue, for the induction of labour in 1993 and its approval for clinical use by ACOG (American College of Obstetrics and Gynecology) in 1999 has been the most significant advancement. It is the latest drug for induction of labour which is cheap and stable at room temperature and is being used worldwide in different doses and by various routes. We compared the most commonly preferred two routes; vaginal and oral in terms of success of induction and noted the adverse events and side effects in both routes.Methods: This was a prospective comparative study carried out at SBKSMIRC (Shrimati Bhikhiben Kanjibhai Shah Medical Institute and Research Centre), Dhiraj general hospital, Vadodara, Gujarat, 200 patients who required induction of labour were recruited after applying inclusion and exclusion criteria and were randomly divided in two groups- Group A meant to receive 50µg oral misoprostol, Group B - meant to receive 25µg vaginal misoprostol repeated 4 hourly up to maximum of five doses. Progress of labour was charted on the partograph. The mean induction delivery interval, mode of delivery, maternal and neonatal outcomes and complications were observed.Results: The mean induction to delivery interval was significantly less in vaginal group than oral (23.3±12.4 hours in oral vs. 17.3±10 hours in vaginal). Vaginal delivery and cesarean section rates were comparable in both groups (76% in Group A vs. 72% in Group B for vaginal delivery, 18% vs. 20% for Cesarean section, respectively). 58% patients in Group A required more than two doses as compared to 39% in group B, though the difference was statistically not significant. Significant number of patients required added oxytocin administration in Group A (72%). No major complications or adverse events were observed. Neonatal hyperbilirubinemia was seen more in Group A.Conclusions: Both Oral misoprostol in a dose of 50μg and vaginal misoprostol 25 μg every four hours, to a maximum of five doses, have the potential to induce labour safely and effectively. The vaginal route however is beneficial in effecting delivery in lesser time with few numbers of doses as compared to oral route.

The efficacy and safety of 25 μg or 50 μg oral misoprostol versus 25 μg vaginal misoprostol given at 4‐ or 6‐hourly intervals for induction of labour in women at or beyond term with live singleton pregnancies: A systematic review and meta‐analysis

“…Eight trials 26,29–31,33–35,37 were conducted in India, three in the USA, 27,28,36 and the others were conducted in Iran 32 and Canada 38 (Table 1). The median age of the mothers, when reported, ranged from 20–40 years.…”

“…The 13 trials included 2941 women at or beyond term with an unfavorable cervix, of whom 1460 were randomized to oral and 1481 to vaginal misoprostol. The trials compared the following: 25 μg oral versus 25 μg vaginal misoprostol given 4‐hourly (three trials, 515 women); 26,28,30 50 μg oral versus 25 μg vaginal misoprostol 4‐hourly (five trials, 900 women); 29,31,33,35,36 50 μg followed by 100 μg oral versus 25 μg vaginal misoprostol 4‐hourly (two trials, 967 women); 27,37 50 μg oral 4‐hourly versus 25 μg vaginal misoprostol 6‐hourly (one trial, 339 women); 38 and 50 μg oral versus 25 μg vaginal 6‐hourly (two trials, 220 women) 28,30 . The trials varied in the maximum number of doses of oral and vaginal misoprostol permitted (Table 1), and not all reported the actual number of doses given.…”

“…Thirteen trials [26][27][28][29][30][31][32][33][34][35][36][37][38] fulfilled the review's eligibility criteria and were included in qualitative and quantitative synthesis (Figure 1). The reasons for excluding 20 potentially relevant studies are provided in Table S2.…”

“…HY, SB and JM are authors of a trial included in this review. 33 However, they were not involved in assessing risk of bias or extracting data from that trial. The authors declare no other conflicts of interest.…”

“…Eight trials 26,[29][30][31][33][34][35]37 were conducted in India, three in the USA, 27,28,36 and the others were conducted in Iran 32 and Canada 38…”