What is the recommended regimen for a second trimester abortion using mifepristone (Mifeprex) and misoprostol (Cytotec) combination versus misoprostol alone?

Second Trimester Abortion: Mifepristone-Misoprostol Combination vs. Misoprostol Alone

The combination of mifepristone and misoprostol is the recommended regimen for second trimester abortion as it is more effective and faster than misoprostol alone. 1

Comparison of Regimens

Mifepristone-Misoprostol Combination (Preferred)

• The combination regimen typically involves mifepristone 200 mg followed by misoprostol 24-48 hours later 1
• Results in 95% complete abortion within 24 hours of misoprostol administration 1
• Reduces time to abortion by 40-50% compared to misoprostol alone 1
• Significantly shorter induction-to-abortion interval (average 9.5-9.7 hours) compared to prostaglandin-only regimens (22.7 hours) 2
• All patients receiving mifepristone followed by prostaglandin abort within 24 hours, compared to only 80% with prostaglandin alone 2

Misoprostol Alone (Alternative)

• Should only be used when mifepristone is not available or affordable 3, 1
• Requires higher total doses to achieve effectiveness 3
• Best administered vaginally or sublingually 1
• Doses of 400 mcg are generally superior to 200 mcg or less 1
• Dosing every 3 hours is more effective than less frequent intervals 1
• Achieves abortion rates of approximately 80-85% at 24 hours 1

Administration Guidelines

Dosing for Mifepristone-Misoprostol Combination

• Mifepristone: 200 mg orally 1
• Followed 24-48 hours later by misoprostol 1
• Misoprostol: 800 mcg administered buccally or vaginally 1, 4

Dosing for Misoprostol Alone

• 400 mcg vaginally or sublingually every 3 hours 1
• Higher doses (600-800 mcg) can be used with longer intervals (up to 12 hours) 1

Safety Considerations

• Second trimester abortions should be performed in a healthcare facility where blood transfusion and emergency surgery (including laparotomy) are available 3
• Dilatation and evacuation is the safest procedure in both first and second trimesters if surgical evacuation is feasible 5
• If surgical evacuation is not feasible, medical methods using prostaglandins can be administered 5
• Misoprostol should be avoided in women with previous cesarean delivery due to the risk of uterine rupture 5, 6
• When prostaglandin E compounds are administered, systemic arterial oxygen saturation should be monitored with a transcutaneous pulse oximeter 5
• Norepinephrine may be needed to support diastolic blood pressure, which reflects systemic vascular resistance 5
• Prostaglandin F compounds should be avoided as they can significantly increase pulmonary arterial pressure and decrease coronary perfusion 5

Expected Effects and Management

• Cramping and bleeding are expected effects, with bleeding lasting an average of 9-16 days 4
• Side effects of misoprostol include gastrointestinal symptoms, fever/rigors, and pain 7
• Adverse effects can be managed with nonsteroidal anti-inflammatory drugs or antiemetics 4
• Efforts should be made to reduce unnecessary surgical evacuation of the uterus after expulsion of the fetus 3

Practical Advantages

• Misoprostol is inexpensive and stable at room temperature, making it more widely available 1, 2
• Medical management avoids anesthesia risks and surgical complications such as uterine perforation, cervical trauma, and Asherman syndrome 7
• The combination regimen provides a non-invasive and effective approach for second trimester termination 2

Monitoring and Follow-up

• Confirm complete passage of pregnancy tissue through clinical history combined with serial quantitative beta human chorionic gonadotropin levels, urine pregnancy testing, or ultrasonography 4
• Monitor for rare complications such as ongoing pregnancy, infection, hemorrhage, or need for unplanned uterine aspiration 4