Induction of labor with high‐ or low‐dosage oral misoprostol—A Danish descriptive retrospective cohort study 2015‐16

Abstract

Introduction:In Denmark, the rate of induced labor from 37 gestational weeks has increased by 108% from 12.4% in 2000 to 25.1% in 2012, and today more than 1 in 4 deliveries are induced. Standard procedure at North Zealand Hospital changed in 2016 from a dosage of 50 µg oral misoprostol 2-3 times daily, to 25 µg up to 8 times daily. Also, since 2016 healthy women with uncomplicated pregnancies (primiparous and multiparous) have been offered induction as an outpatient procedure. This study aimed to compare the current low-dosage procedure (25 µg) with the former highdosage procedure (50 µg) in terms of induction to delivery time, maternal and fetal outcomes, and risk of uterine hyperstimulation. Material and methods:Data from June 2015 to October 2016 were included.Comparable baseline, demographic, and obstetric data for women induced according to high-dosage or low-dosage protocols were retrieved from local medical files.Descriptive statistics, Pearson's chi-squared tests, Kaplan-Meier survival estimates, and logistic regression analyses were performed. Results:The study included 816 induced deliveries. The high-and low-dosage groups differed in rates of plurality and place of induction. Induction to delivery times lasting longer than 72 hours were significantly decreased in the low-dosage group (adjusted odds ratio [aOR] 0.48, 95% confidence interval [95% CI] 0.27 to 0.86). Women in the low-dosage group also less often needed additional induction (P = 0.02), and the rate of uterine hyperstimulation was low irrespective of protocol (1% vs 3%, P = 0.16).There were no cases of uterine rupture in either group. The probability of vaginal delivery in the low-dosage group increased (adjusted hazard ratio 1.27, 95% CI 1.08 to 1.49), as did the risk of delivery with vacuum extraction (aOR 2.27, 95% CI 1.24 to 4.15), whereas delivery by cesarean section slightly decreased (aOR 0.89, 95% CI 0.59 to 1.33). The risk of meconium-stained liquor was nonsignificantly decreased (aOR 0.82, 95% CI 0.55 to 1.23). Conclusions: The low-dosage induction protocol was associated with favorable obstetric outcomes in terms of increased probability of vaginal delivery, but with higher risk of vacuum extraction. Protracted inductions and additional nonmedical interventions were reduced. There were no cases of uterine rupture. Statistically | 223 BENDIX Et al. How to cite this article: Bendix JM, Friis Petersen J, Andersen BR, Bødker B, Løkkegaard EC. Induction of labor with high-or low-dosage oral misoprostol-A Danish descriptive retrospective cohort study 2015-16. Acta Obstet Gynecol Scand. 2020;99:222-230. https ://doi.

An audit of oral administration of Angusta® (misoprostol) 25 µg for induction of labor in 976 consecutive women with a singleton pregnancy in a university hospital in Denmark

“…In our study, the overall rate of CS after IOL was 14.9%, which is comparable to the frequency of 16% among women with a similar low‐dosage regimen 8 . More than half of the CS with the outpatient regimen were due to dystocia and only few were because of failed induction.…”

“…Postpartum hemorrhage ≥1000 ml occurred in 10.5% of women in the audit, which is slightly higher than the general rate in the department of 9.3% but similar to the result in the low‐dosage regimen mentioned above 8 . It is well known, however, that induced labors are associated with an increased risk of postpartum hemorrhage 16 …”

“…It is a strength of this audit that all inductions were handled according to a predefined regimen and that a misoprostol tablet manufactured for IOL with a known content of the active agent was used for IOL. With the exception of a recent Danish study, 8 previous published studies on oral misoprostol for IOL have used 200‐µg misoprostol tablets in solution or have divided the tablets into four or more parts, potentially resulting in varying doses of the active substance.…”

Factors of Non-Compliance with a Protocol for Oral Administration of Misoprostol (Angusta®) 25 Micrograms to Induce Labor: An Observational Study

“…Median time to delivery was significantly shorter in the group with compliant administration (23 h vs. 29 h, p = 0.004). In the literature, there is still a lack of data to establish a clear protocol with a precise dose and frequency of administration [ 19 , 20 ]. It is a strength of this study that all inductions were handled according to a predefined protocol and that a misoprostol tablet manufactured for IOL with a known content of active agent was used.…”

Italian Society of Gynaecology and Obstetrics (SIGO): Consensus paper on induction of labor with oral administration of Misoprostol

“…Compared to the use of high doses (50 mcg), induction with Misoprosol 25 mcg shows a more favourable obstetric outcome and a higher probability of a successful vaginal birth. The actual percentage of an assisted birth with vacuum or forceps following IOL with Misoprostol is yet to be defined, as some studies hypothesise that low doses (25 mcg) of Misoprostol may increase this risk (25). The first dose of Misoprostol must be administered after a 30-minute reactive Non Stress Test (NST) (26).…”