What are the guidelines for medical termination of pregnancy by trimester?

Medical Termination of Pregnancy According to Trimester

Medical termination of pregnancy should be performed using different protocols based on gestational age (trimester), with first-trimester procedures being the safest and most effective, while second and third-trimester terminations require more specialized approaches to minimize maternal morbidity and mortality.

First Trimester (Up to 12 Weeks)

Recommended Methods:

• Medication abortion is highly effective with complete abortion rates of approximately 95% 1
• The recommended regimen is 200 mg mifepristone followed by 800 μg misoprostol 24-48 hours later 1
• If mifepristone is unavailable, misoprostol alone can be used, though repeated doses may be required and efficacy may be lower 1
• Vacuum aspiration (VA), either by electrical suction or manual aspiration, is the surgical method of choice with approximately 97% complete abortion rate 1

Safety Considerations:

• Risk of significant bleeding is ≤5% with vacuum aspiration, while major complications occur in <1% 1
• Prophylactic antibiotics or screen-and-treat strategy significantly reduces infection risk 1
• Pre-operative misoprostol administration can reduce procedural complications 1
• No lower limit of gestational age exists for termination, though extra precaution is required to confirm completion and exclude ectopic pregnancy 1

Second Trimester (13-28 Weeks)

Recommended Methods:

• Dilation and evacuation (D&E) is the safest procedure for second-trimester termination, with lower complication rates compared to medical methods 2
• D&E has lower risk of hemorrhage (9.1% vs 28.3% with medical methods) and infection (1.3% vs 23.9% with medical methods) 2
• Medical termination using mifepristone combined with misoprostol has the highest efficacy and shortest abortion interval 3
• Where mifepristone is unavailable, misoprostol alone is a reasonable alternative 3

Medical Protocol:

• For gestational age <30 weeks: 800 μg misoprostol administered intravaginally, followed by 400 μg orally every 3 hours (maximum 3 additional doses) if no contractions occur 4
• Vaginal administration of prostaglandins at 3-hourly intervals results in shorter induction-to-abortion interval than 6-hourly administration without increased side effects 3
• Misoprostol is preferably administered vaginally, although sublingual administration appears equally effective in multiparous women 3

Special Considerations:

• Patients with placenta previa and previous cesarean delivery require careful evaluation as they may need specialized management 5
• Most common side effects include mild self-limiting diarrhea and pain 3

Third Trimester (Beyond 28 Weeks)

Recommended Methods:

• For gestational age >30 weeks: Lower initial dose of misoprostol (50 μg intravaginally) increased to 100 μg every 3 hours until expulsion, due to increased risk of uterine rupture 4
• Medical termination should be performed in a hospital setting with close monitoring 2

Special Considerations:

• Anesthesia and pain management should be provided, with most D&E procedures performed under sedation or general anesthesia 2
• Fetal analgesia is not recommended during pregnancy termination procedures as there is no evidence of fetal pain awareness before 24-25 weeks gestation 2

Post-Procedure Care (All Trimesters)

• Antibiotic prophylaxis is recommended to prevent post-abortal endometritis, which occurs in 5-20% of women not given antibiotics 2
• Rh-negative women should receive anti-D immunoglobulin to prevent alloimmunization 2
• Monitor for signs of infection, retained products, and excessive bleeding 2

Special Situations

Pregnancy with Cancer:

• First trimester: Termination of pregnancy is advised if chemotherapy or radiotherapy administration is required, as these treatments during the first trimester are associated with high risk of fetal malformations 6
• Second and third trimesters: Chemotherapy can be administered with reasonable safety, though there is increased risk of stillbirth, growth retardation, and premature delivery 6
• Anthracycline-based regimens are the most studied during pregnancy and remain the first choice if treatment cannot be delayed 6

Twin Pregnancies with Hydatidiform Mole:

• Early termination does not decrease the risk of subsequent gestational trophoblastic neoplasia 6
• Early pregnancy termination should be performed by suction curettage 6
• In late pregnancy, termination is more complex and depends on gestational age, size of uterus, and maternal risks 6

Patients with End-Stage Renal Disease:

• Mifepristone can be used up to 7 weeks gestation as an alternative to surgical evacuation 7
• These patients should be considered high-risk and managed in experienced centers with appropriate emergency support services 7
• Baseline assessment of renal function, electrolytes, and potential bleeding risks should be performed before the procedure 7