Pharmaceutical Abortion Regimen for Early Pregnancy
Recommended Regimen
For a healthy woman with confirmed intrauterine pregnancy <10 weeks (≤70 days) gestation, administer mifepristone 200 mg orally followed by misoprostol 800 mcg administered buccally or vaginally, with the misoprostol given 24-48 hours after mifepristone. 1
Evidence-Based Dosing Algorithm
Mifepristone Administration
- Dose: 200 mg orally 2, 1, 3
- Timing: Day 1 of treatment 1
- Setting: Can be administered in office or clinic 2
Misoprostol Administration
- Dose: 800 mcg 2, 1
- Route: Buccal or vaginal administration (both equally effective) 1
- Timing: 24-48 hours after mifepristone 1, 3
- Setting: Self-administered at home 2, 3
Alternative Timing Option
- Simultaneous administration (misoprostol given same day as mifepristone, 6-8 hours apart) demonstrates comparable efficacy (95.1% complete abortion rate) and is noninferior to the 24-hour interval regimen 2, 4
- This same-day regimen is effective through 63 days gestation 2, 4
Efficacy by Gestational Age
- ≤49 days: Success rates 92-97% 5
- 50-56 days: 100% complete abortion rate 4
- 57-63 days: 98% complete abortion rate 4
- Overall ≤63 days: 94-97% success rate with standard 24-hour interval regimen 2, 3
Expected Clinical Course
Normal Effects
- Cramping and bleeding are expected therapeutic effects 1
- Bleeding duration: Average 9-16 days 1
- Expulsion timing: Most women (90-93%) expel pregnancy tissue within 24 hours of misoprostol administration 4
Management of Adverse Effects
- Misoprostol-related symptoms (low-grade fever, nausea, diarrhea, gastrointestinal symptoms): Treat with NSAIDs or antiemetics 1
- Pain management: NSAIDs are first-line 1
Follow-Up and Confirmation
Assessment Methods
- Clinical history combined with one of the following 1:
- Serial quantitative beta-hCG levels
- Urine pregnancy testing
- Ultrasonography
- Timing: Follow-up evaluation 7±1 days after initiating treatment 2
Second Dose Protocol
- If bleeding is less than normal menstrual period at 24 hours after initial misoprostol dose, administer second similar dose of misoprostol 3
- Women who have not aborted at first follow-up should be offered second dose of misoprostol 2
Pre-Treatment Requirements
Gestational Age Confirmation
- Determined using ultrasonography or menstrual history 1
- Ultrasonography is required when:
Contraindications (Critical Safety Considerations)
- Pregnancy must be confirmed intrauterine before administration 1
- Mifepristone causes termination of pregnancy and is absolutely contraindicated in women who wish to continue pregnancy 6, 7
- Misoprostol can cause uterine rupture when used to induce labor or abortion beyond 8 weeks in certain contexts 7
Rare Complications to Monitor
- Ongoing pregnancy 1
- Infection 1
- Hemorrhage 1
- Undiagnosed ectopic pregnancy 1
- Need for unplanned uterine aspiration 1
Post-Abortion Contraception Counseling
- Fertility returns immediately: Ovulation can occur before first menstrual period 8
- Contraception timing: Can be initiated within first 7 days after abortion, including immediately post-procedure 8
- Combined hormonal contraceptives: Require 7 days backup contraception unless started at time of surgical abortion 8
- Progestin-only methods: Require only 2 days backup contraception 8
Common Clinical Pitfalls to Avoid
- Do not delay treatment based solely on inability to perform ultrasonography if clinical dating is reliable and ectopic pregnancy risk is low 5
- Do not assume absence of bleeding means treatment failure—some women may have delayed expulsion 1
- Do not use hormonal contraceptives for pregnancy prevention during mifepristone treatment, as mifepristone reduces their effectiveness 6
- Ensure patient understands that bleeding and cramping are expected therapeutic effects, not complications 1