BACKGROUND
NICE recommends oral misoprostol as an alternative IOL (induction of labour) agent.
Associated with increased vaginal birth within 24 hrs (RR 0.78) vs intracervical prostaglandins1
Lower caesarean rates vs vaginal prostaglandins (RR 0.87)1
Royal London Hospital: 5,000+ births/year; 28% require IOL
AIM
Improve patient flow & reduce inpatient stay.
Enhance patient & staff experience.
Ensure patient safety with cost-effective implementation
METHODOLOGY
Oral misoprostol protocol: 25mcg every 2 hours, max 8 doses/day
Cohorts: misoprostol (Aug–Sept 2024) vs dinoprostone (Aug–Sept 2023)
Retrospective analysis of delivery mode and time from IOL to birth
Data collected on maternal/neonatal adverse outcomes
DEMOGRAPHICS
86 patients opted in to misoprostol cohort
Maternal age 19-52 years; 53% patients between 25-34 years,67% identify as South Asian
41% BMI 18.5-24.9, 24% overweight and 23% obese
67% primips, 33% multips
IOL indications - reduced fetal movements (24%), gestational diabetes (16%) and postdates (14%)
85 patients identified in dinoprostone cohort; maternal age 21-44 years
64% primips, 36% multips
RESULTS
Vaginal Birth Rates
Misoprostol: 57% (n=49) overall; 46.6% in primigravidas, 78.6% in multiparous patients
Dinoprostone: 75% (n=64) overall; 64.8% in primigravidas, 93.5% in multiparous patients
Labour Progress & Misoprostol Dosing
Average of 6 doses of misoprostol required before artificial rupture of membranes (ARM)
72% were ≥2 cm dilated upon transfer to the labour ward
88% of successful inductions required ≤8 doses
Timing of Vaginal Birth
Vaginal birth within 24 hours: slightly lower with misoprostol RR 0.90 (95% CI 0.50-1.63, p=0.73)
Vaginal birth within 48 hours: slightly higher with misoprostol RR 1.03 (95% CI 0.75-1.42, p=0.85)
Mode of Delivery
Higher rate of emergency caesarean with misoprostol (RR 1.74, 95% CI 1.18–2.71, p=0.01)
Induction failure: 9% (misoprostol) vs 2% (dinoprostone)
Emergency caesarean for labour dystocia: 10% (misoprostol) vs 7% (dinoprostone)
Maternal & Neonatal Safety
Misoprostol associated with fewer adverse outcomes overall: hyperstimulation RR 0.13 (95% CI 0.17-1.05, p=0.06), CTG abnormalities RR 0.43 (95% CI 0.20-0.92, p=0.03), antepartum haemorrhage RR 0.99 (95% CI 0.06-15.55, P=0.99), postpartum haemorrhage RR 0.65 (95% CI 0.41-1.03, p=0.07), NICU admissions RR 0.41 (95% CI 0.08-2.05, p=0.28)
No increased risk of serious adverse events, though higher rates seen for: maternal pyrexia RR 1.47 (95% CI 0.26-8.56, p=0.68), meconium-stained liquor RR 1.21 (95% CI 0.51-2.91, P=0.66), low APGAR scores RR 1.95 (95% CI 0.18-21.16, P=0.58) - none statistically significant
DISCUSSION AND CONCLUSION
Misoprostol is a patient-friendly oral option.
Misoprostol introduction was a cost neutral measure
Data suggests good safety profile with few adverse events but lower vaginal birth rate
Additional choice for mode of IOL – liked by patients.
Small cohort size & wide CIs limit conclusion strength.
Pilot ongoing; expanding sample to strengthen data.
50mcg oral solution trial in progress.
REFERENCES
1World Health Organization (2011). WHO recommendations for induction of labour. World Health Organization. https://iris.who.int/handle/10665/44531
2MedCalc Software Ltd. Relative risk calculator. https://www.medcalc.org/calc/relative_risk.php (Version 23.2.6; accessed June 9, 2025)
