Oral or Vaginal Misoprostol for Labor Induction and Cesarean Delivery Risk

Abstract

OBJECTIVE: To evaluate whether cervical ripening with oral misoprostol increases cesarean delivery risk and prolongs time to vaginal delivery compared with vaginal misoprostol in a predominantly overweight population. METHODS: This single center, retrospective cohort study was performed at a tertiary care academic medical center and compared labor induction outcomes with vaginal misoprostol to outcomes with oral misoprostol after a complete institutional shift to oral misoprostol. Labor induction using 25 micrograms vaginal misoprostol in 2013–2014 was compared with 50 micrograms oral misoprostol in 2014–2015. The primary outcome was cesarean delivery. Secondary outcomes included time to vaginal delivery, uterine tachysystole, maternal hemorrhage, and composite adverse neonatal outcomes. Demographics and outcomes were analyzed using standard statistical tests. Multivariable regression models accounting for potential confounders were created for the primary and secondary outcomes with adjusted odds ratios (aOR) as the measures of effect. RESULTS: There were 138 women in the oral and 138 women in the vaginal misoprostol groups. In the overall cohort, the median (interquartile range) body mass index was 31.7 (28.2–36.8) and most women (72%) were of either black or Hispanic race or ethnicity. The frequency of cesarean delivery was higher in the oral than the vaginal misoprostol group (32% vs 21%; P=.04). The adjusted odds of cesarean was higher with oral misoprostol (aOR 2.01; 95% CI 1.07–3.76). Among nulliparous women, the frequency of cesarean delivery was 41% in the oral and 28% in the vaginal misoprostol groups (aOR 2.79; 95% CI 1.26–6.19). Women had a longer time to vaginal delivery in the oral compared with vaginal misoprostol group (41 vs 31 hours respectively, P=.01). Tachysystole occurred more frequently with vaginal misoprostol (20% vs 11%; P=.04). CONCLUSION: Compared with vaginal misoprostol, oral misoprostol may be associated with increased risk of cesarean delivery and longer time to vaginal delivery.

Oral misoprostol solution in comparison to vaginal misoprostol for induction of labour in a randomized controlled trial

“…This was not in consistence with finding by many studies. [23][24][25] While Mahajan study in 2018 had the same finding as the current study. 18 This could be explained as well as expected as different dosage regimen between these studies and this study.…”

“…This wasn't the same as results of many studies revealing higher rate of Tachy systole with vaginal route of administration and again it may be expected with the understand of pharmacokinetics of misoprostol. 24,26,27,32 While studies done by had no difference in occurrence of uterine tachysystole and by in depth read of all these studies authors could owe this difference in different dose used orally and its impact on induction delivery time as well as uterine tachysystole. 25,30 The neonatal outcome at the end of the study was the same in both groups and this in consistent with many of the previous published data.…”

“…For vaginal administration, the onset of action is 20 minutes, T-max is 70 minutes and duration of action is 4 hours, hence vaginal misoprostol remains effective for longer time and hence lesser dosage is required for induction of labour, assessment of routes of administration rather than vaginal route remain an area of research. 24 The current research study was 153 study subjects assessed for eligibility to be recruited for the research study in which 53 of them were excluded from.100 study subjects remaining were categorized in two research groups 50 cases in each the oral misoprostol research group and the vaginal misoprostol research group. Of them 48 and 47 subjects were analyzed.…”

“…This was same conclusion made by Mahajan et al and Handal-Orefice et al agreed with this findings regarding oxytocin augmentation and dose, while Cheng in 2008 and Souza in 2013 reported a greater need for oxytocin in women using oral misoprostol (57%) than in those with vaginal administration (51%). 18,24,27,28 Relative risk for need of intervention with the oral route compared to the vaginal route was calculated to be 0.50, i.e., risk for need of intervention using oral misoprostol was half that of the vaginal route. However, this finding lacked statistical significance, so authors didn't find any statistically significant difference between both groups regarding rate of interventions, operative vaginal delivery or CS rate.…”

“…and this was going hand in hand with many other studies. 18,24,26,29,30 While two studies before found higher risk of CS with oral misoprostol but by looking more in depth this difference may be due to many points, Handal-Orefice study was retrospective, comparing both routs in different period of time and the studied group wasn't homogenous regarding many inclusion criteria like BMI. 27,31 However, no statistically significant differences were found between both groups regarding the incidence of uterine hyperstimulation or fever.…”