MTP medical abortion protocol
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mifepristone misoprostol medical abortion protocol
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MTP medical abortion protocol mifepristone misoprostol WHO 2022 guidelines gestational limits
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Here is a comprehensive reference on the MTP (Medical Termination of Pregnancy) - medical abortion protocol, based on WHO 2022 guidelines, RCOG guidance, and Goldman-Cecil Medicine.
MTP - Medical Abortion Protocol
Overview
Medical abortion (pharmacological termination) uses antiprogestins and/or prostaglandins to terminate pregnancy without surgery. The preferred regimen is mifepristone + misoprostol, which is more effective than misoprostol alone.
Mechanism of Action
| Drug | Class | Mechanism |
|---|---|---|
| Mifepristone | Antiprogestin / antiglucocorticoid | Competitively blocks progesterone receptors → decidual necrosis, cervical softening, sensitizes uterus to prostaglandins |
| Misoprostol | Synthetic PGE1 analogue | Uterine contractions, cervical ripening/dilatation → expulsion |
First-Trimester Protocol (< 12 Weeks / < 63–70 days)
Recommended Regimen (WHO 2022 / FDA-approved)
| Step | Drug | Dose | Route | Timing |
|---|---|---|---|---|
| 1 | Mifepristone | 200 mg | Oral (PO) | Day 1 |
| 2 | Misoprostol | 800 mcg | Vaginal (PV), Sublingual (SL), or Buccal (B) | 24-72 hrs after mifepristone |
- Success rate: 94-98% (Goldman-Cecil Medicine)
- Gestational limit: Up to 63 days (9 weeks) per FDA approval; WHO extends this to < 12 weeks with the same regimen
- The minimum interval between mifepristone and misoprostol is 24 hours
- A 2025 Society of Family Planning guideline (PMID: 40122324) specifically addresses management at < 42 days gestation, including pregnancy of unknown location
Misoprostol-Only Regimen (if mifepristone unavailable)
- Misoprostol 800 mcg by vaginal, sublingual, or buccal route
- Repeat doses may be needed, especially at ≥ 9 weeks; WHO places no maximum on number of doses
- Slightly less effective than the combination regimen
Letrozole + Misoprostol (Alternative, < 12 weeks)
- Letrozole 10 mg PO daily × 3 days, then misoprostol 800 mcg SL on Day 4
- May be safe and effective up to 14 weeks; useful where mifepristone is unavailable (WHO 2022)
Second-Trimester Protocol (≥ 12 Weeks)
Combination Regimen (WHO 2022)
| Step | Drug | Dose | Route | Interval |
|---|---|---|---|---|
| 1 | Mifepristone | 200 mg | Oral | 24-48 hrs before misoprostol |
| 2 | Misoprostol | 400 mcg | PV, SL, or Buccal | Every 3 hours |
Misoprostol-Only (if mifepristone unavailable)
- Misoprostol 400 mcg PV, SL, or Buccal every 3 hours
Late Second Trimester / > 24 Weeks (RCOG guidance)
| Gestation | Mifepristone | Misoprostol dose | Interval |
|---|---|---|---|
| 24-25 weeks | 200 mg PO | 400 mcg (PV/SL/Buccal) | Every 3 hours |
| 25+1 to 28 weeks | 200 mg PO | 200 mcg (PV/SL/Buccal) | Every 4 hours |
| > 28 weeks | 200 mg PO | 100 mcg (PV/SL/Buccal) | Every 6 hours |
Note: Doses are progressively reduced as gestational age increases due to greater uterine sensitivity to prostaglandins.
Special Indications (WHO 2022 Summary Chart)
| Indication | Mifepristone | Misoprostol |
|---|---|---|
| Induced abortion < 12 weeks | 200 mg PO once | 800 mcg PV/SL/Buccal once |
| Induced abortion ≥ 12 weeks | 200 mg PO once | 400 mcg PV/SL/Buccal q3h |
| Missed abortion < 14 weeks | 200 mg PO once | 800 mcg Buccal/PV/SL |
| IUFD 14-28 weeks | 200 mg PO once | 400 mcg PV or SL q4-6h |
| Incomplete abortion < 14 weeks | - | 600 mcg PO or 400 mcg SL once |
Surgical Methods (by gestational age)
When medical abortion fails or is contraindicated:
| Gestational Age | Procedure |
|---|---|
| < 14 weeks | Manual or electric vacuum aspiration (MVA/EVA) |
| ≥ 14 weeks | Dilatation and evacuation (D&E) |
| Late (> 19 weeks) | D&E or medical induction combined with medication |
Expected Clinical Course
- Bleeding and cramping typically begin 1-4 hours after misoprostol
- Expulsion of products of conception usually occurs within 4-8 hours
- Side effects include nausea, vomiting, diarrhea, abdominal pain, and fever (from misoprostol)
Complications and Rates
| Complication | Rate |
|---|---|
| Blood transfusion required | ~0.05% (first trimester) |
| Retained products / incomplete | 5-8 per 100 |
| Need for further surgical intervention | ~13 per 100 |
| Infection | < 2 per 100 |
| Severe bleeding (< 20 weeks) | < 1 per 1000 |
| Severe bleeding (> 20 weeks) | ~4 per 1000 |
| Uterine rupture | < 1 per 1000 |
Contraindications to Medical Abortion
- Confirmed or suspected ectopic pregnancy (absolute)
- IUD in situ (remove before treatment)
- Inherited porphyria (mifepristone)
- Long-term systemic corticosteroid use (mifepristone, due to antiglucocorticoid effect)
- Coagulopathy or anticoagulant therapy (relative)
- Adrenal insufficiency (mifepristone)
Follow-up
- A routine follow-up visit is recommended after misoprostol-only regimens to confirm complete expulsion
- For mifepristone + misoprostol regimens, clinical assessment (serum hCG, ultrasound, or symptom review) is needed if expulsion is uncertain
- Surgical completion (MVA/D&C) is required in case of medication failure
Prescribing Notes (US Context)
- Providers must register with the manufacturer (REMS program) to prescribe mifepristone
- Telemedicine prescribing is supported by evidence and is FDA-permitted as of 2023
- Local/state regulations may impose additional requirements on counseling, gestational limits, or administration settings
Sources:
- WHO 2022 Abortion Care Guideline summary chart
- Goldman-Cecil Medicine (International Edition), Reproductive Health Issues chapter
- RCOG Medical abortion from 12 weeks
- Society of Family Planning Clinical Recommendation 2025 PMID: 40122324
- Cochrane Review 2025 on second-trimester methods PMID: 40626417
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