WHO Guidelines on Misoprostol Usage
I cannot provide specific WHO guidelines from the evidence provided, as none of the documents are actual WHO publications - they are primarily BJOG/RCOG guidelines (2025), Society of Family Planning recommendations (2025), and older research studies.
However, I can provide the most current evidence-based recommendations from the highest-quality guidelines available:
Medical Abortion (14-27 weeks gestation)
For medication abortion between 14-27 weeks, use mifepristone 200 mg followed by misoprostol in gestational age-specific dosing 1:
- Mifepristone 200 mg (single dose)
- Wait 24-48 hours, then start misoprostol:
- 14-22 weeks: 400 mcg sublingual/buccal every 3 hours
- Continue until complete expulsion (usually within 48 hours)
- Most patients need ≤6 doses of misoprostol
If mifepristone unavailable, misoprostol-only regimens are less effective but acceptable 1:
- 400-600 mcg vaginally every 4-6 hours (higher doses more effective)
- Expect longer induction-to-abortion intervals (11-12 hours vs 7 hours with combination)
Labour Induction for Intrauterine Fetal Death (Late Second/Third Trimester)
Vaginal misoprostol is as effective as oral but with fewer adverse effects 2:
Recommended regimen after mifepristone 200 mg:
- 24+0-24+6 weeks: 400 mcg every 3 hours
- 25+0-27+6 weeks: 200 mcg every 4 hours
- ≥28+0 weeks: 25-50 mcg vaginal every 4 hours OR 50-100 mcg oral every 2 hours
Critical caveat: Evidence for optimal dosing ≥28 weeks is insufficient, particularly with prior cesarean delivery 2. Women with >2 prior cesareans or atypical scars should be counseled that safety is unknown.
Incomplete Abortion (First Trimester)
Single dose of 600 mcg oral misoprostol is recommended for incomplete abortion ≤12 weeks gestation 3:
- One-time administration
- Safe and effective for non-surgical uterine evacuation
- Do not use beyond 12 weeks - approximately 75% require MVA at 13-18 weeks with 25% experiencing severe bleeding 4
Postpartum Hemorrhage
Prevention
600 mcg oral or sublingual misoprostol is indicated when injectable oxytocin is unavailable 5, 6:
- More effective than placebo in community births (RR 0.59)
- Less effective than oxytocin (RR 1.34) - use oxytocin when available
- Associated with increased side effects: fever >38°C (RR 8.07), tremors (RR 2.80), GI symptoms
Treatment
800 mcg sublingual misoprostol can be used for uterine atony when oxytocin unavailable 5:
- Equivalently stops active bleeding compared to oxytocin 40 IU IV (RR 1.12)
- Wait minimum 2 hours before repeat dose; if initial dose caused fever/shivering, wait ≥6 hours
- Higher side effect profile than oxytocin
Important safety warning: Rare but potentially lethal hyperpyrexia leading to rhabdomyolysis and convulsions has been reported, particularly with sublingual route 7. Consider prophylactic antipyretics.
Critical Safety Considerations
Contraindications per FDA labeling 8:
- Pregnancy (when used for NSAID ulcer prevention)
- Can cause abortion, premature birth, birth defects
- Uterine rupture risk with labor induction, especially with prior cesarean
Avoid misoprostol for labor induction in women with previous cesarean delivery 9 - documented uterine rupture risk, though magnitude unclear 10.
Common pitfalls: