Medical Abortion Options and Side Effects
Medication Regimen
The standard medical abortion regimen consists of mifepristone 200 mg orally followed by misoprostol 800 mcg administered buccally or vaginally, which is safe and effective for pregnancy termination up to 77 days (11 weeks) gestation. 1
Dosing Protocol
- Mifepristone 200 mg is taken orally first, which blocks progesterone receptors and causes decidual breakdown of the uterine lining 2
- Misoprostol 800 mcg follows 24-48 hours later, though simultaneous administration is equally effective 3
- Misoprostol can be self-administered at home either buccally (between cheek and gum) or vaginally 1, 4
- A second dose of misoprostol may be taken 24 hours after the first if bleeding is less than a normal menstrual period 4
Efficacy
- Complete abortion rates range from 92-97% without surgical intervention 1, 5, 6
- Success rates remain consistent across gestational ages up to 63 days 3
- By day 7 after treatment, 95% of women achieve complete abortion 5
- Incomplete abortion requiring surgical intervention occurs in 3-5% of cases 6
Expected Effects and Timeline
Bleeding Pattern
- 80% of women begin bleeding within 4 hours of misoprostol administration 5
- 98% experience bleeding within 24 hours 5
- Bleeding lasts an average of 9-16 days 1
- Cramping and bleeding are expected therapeutic effects, not complications 1
Common Side Effects
Gastrointestinal Symptoms
- Nausea (very common) 7
- Vomiting 7
- Diarrhea 8, 3
- These symptoms are primarily caused by misoprostol and can be managed with antiemetics 1
Other Frequent Side Effects
- Headache (44% of patients) 7
- Fatigue (48% of patients) 7
- Dizziness (22% of patients) 7
- Low-grade fever from misoprostol 1
- Warmth or chills 3
- Decreased appetite (20% of patients) 7
Pain Management
- Cramping is expected and increases with gestational age 4
- Nonsteroidal anti-inflammatory drugs (NSAIDs) are recommended for pain control 1
Serious Complications (Rare)
Life-Threatening Risks
- Hemorrhage requiring transfusion, hospitalization, or surgery (rare) 6
- Infection/endometritis (rare) 1, 6
- Ongoing pregnancy (1-2% of cases) 6
- Undiagnosed ectopic pregnancy 1
Cardiovascular Concerns
- QT interval prolongation - mifepristone prolongs the QTc interval in a dose-related manner 7
- Caution in patients with underlying heart conditions including heart failure and coronary vascular disease 7
Metabolic Effects
- Hypokalemia (decreased blood potassium) occurs in 34-44% of patients 7
- Potassium levels should be checked before starting treatment and corrected if low 7
- Responds to potassium supplementation and/or mineralocorticoid antagonists like spironolactone 7
Endocrine Effects
- Adrenal insufficiency - mifepristone blocks cortisol action 7
- Symptoms include unusual tiredness, weakness, nausea, fatigue, low blood pressure, and low blood sugar 7
- Vaginal bleeding from endometrial thickening (14% of females in clinical trials) 7
- TSH elevations may occur but typically resolve without intervention 7
Absolute Contraindications
High-Risk Conditions Requiring Alternative Management
- Previous cesarean delivery - misoprostol should be avoided due to uterine rupture risk 8
- Chronic corticosteroid therapy for life-saving conditions (e.g., organ transplant immunosuppression) 7
- Confirmed or suspected ectopic pregnancy 1
Drug Interactions
- Avoid grapefruit juice - increases mifepristone blood levels and side effect risk 7
- Strong CYP3A inhibitors (ketoconazole, itraconazole, ritonavir, clarithromycin) require dose limitation to 900 mg/day maximum if used together 7
Special Populations
High-Risk Patients
- Patients with end-stage renal disease, heart disease, or other serious conditions should be managed in experienced centers with emergency support services 8, 9
- Dilatation and evacuation remains the safest procedure for high-risk patients in both first and second trimesters 8, 9
Rh-Negative Patients
- RhD testing and Rh immune globulin (RhIg) administration should be offered when logistically and financially feasible 10
- A 50 mcg dose within 72 hours is adequate for first-trimester abortion, though 300 mcg may be used if the lower dose is unavailable 10
- If RhD testing would delay abortion access, priority is completing the abortion with counseling about potential risks 10
Follow-Up Requirements
- Evaluation 7±1 days after treatment initiation, typically including transvaginal ultrasonography 3
- Clinical history combined with serial quantitative beta-hCG levels, urine pregnancy testing, or ultrasonography confirms complete passage of pregnancy tissue 1
- Women who have not aborted by first follow-up may be offered a second misoprostol dose 3