Most Appropriate Medical Abortion Regimen for a 9-Week Pregnancy
The most appropriate medical abortion regimen for a 9-week pregnancy is mifepristone 200 mg orally followed by misoprostol 800 mcg vaginally 24-48 hours later.
Medication Protocol
First-Line Regimen
- Day 1: Mifepristone 200 mg orally
- Day 2-3 (24-48 hours later): Misoprostol 800 mcg vaginally
Efficacy and Evidence
- This regimen has a complete abortion rate of 96.9% when misoprostol is administered 24 hours after mifepristone 1
- Vaginal administration of misoprostol is more effective than oral administration for pregnancies at 9 weeks (63 days) gestation 2
- Low-dose mifepristone (200 mg) is as effective as the higher dose (600 mg) regimen, with complete abortion rates of 97% 3
Clinical Considerations
Pre-Abortion Assessment
- Confirm gestational age (≤63 days/9 weeks for this regimen)
- Screen for contraindications to medical abortion
- Consider ultrasonography if:
- Gestational dating cannot be confirmed clinically
- Risk factors for ectopic pregnancy exist 4
Patient Education
- Explain expected effects: cramping and bleeding (average duration 9-16 days) 4
- Discuss potential side effects of misoprostol:
- Nausea
- Diarrhea
- Low-grade fever
- Chills or warmth
- Advise that these side effects can be managed with NSAIDs or antiemetics 4
Follow-up Assessment
- Schedule follow-up visit 7-14 days after treatment
- Confirm complete abortion through:
- Clinical history
- Serial quantitative beta-hCG levels, or
- Ultrasonography 4
Important Warnings and Precautions
Contraindications
- Known allergy to mifepristone or misoprostol
- Confirmed or suspected ectopic pregnancy
- IUD in place (must be removed before medication administration)
- Chronic adrenal failure
- Concurrent long-term corticosteroid therapy
- Hemorrhagic disorders or concurrent anticoagulant therapy
Potential Complications (Rare)
- Ongoing pregnancy (1-4%)
- Infection (<1%)
- Hemorrhage requiring transfusion (<1%)
- Need for unplanned uterine aspiration (2-5%)
Special Considerations for Rh Status
- For RhD-negative women, administer RhIg (50 mg dose is adequate for first trimester) within 72 hours of the abortion 5
- If 50 mg dose is unavailable, a 300 mg dose is acceptable 5
Alternative Regimens
If vaginal administration is not preferred:
- Mifepristone 200 mg orally followed by misoprostol 800 mcg buccally 24-48 hours later 4
If simultaneous administration is necessary (though slightly less effective):
- Mifepristone 200 mg orally and misoprostol 800 mcg vaginally administered simultaneously (95.1% effective) 1
The evidence clearly supports that the combination of mifepristone followed by vaginal misoprostol provides the highest efficacy rates for medical abortion at 9 weeks gestation, with an acceptable safety profile and high patient acceptability.