BACKGROUND AND PURPOSE:

• Liu et al. (Annals of Internal Medicine, 2023) compared short-term risk for adverse outcomes after early mifepristone–misoprostol induced abortion (IA) vs procedural IA

METHODS:

• Population-based cohort study
• Population
  • Women who had first-trimester IA
• Exposure
  • Comparison 1
    • Pharmaceutical IA: Outpatient mifepristone–misoprostol
    • Procedural IA: Performed at ≤14 weeks in nonhospital outpatient clinics
  • Comparison 2
    • Pharmaceutical IA
    • Procedural IA performed at ≤9 weeks at ambulatory hospital-based clinics
• Study design
  • Confounding between exposure groups was included in estimated risk calculations
• Primary outcomes
  • Composite of any serious adverse events within 42 days after IA: Severe maternal morbidity | End-organ damage | ICU admission | Death
  • Broader composite outcome: Any serious adverse event | Hemorrhage | Retained products of conception | Infection | Transfusion

RESULTS:

• Pharmaceutical: 39,856 women | Procedural, nonhospital: 65,176 | Procedural, hospital: 8861
  • Mean age at IA: 29 (SD, 7) years
  • Primigravid: 33%
  • Resided in rural areas: 6% | Resided in low-income neighborhoods: 25%

Comparison 1

• The risk of serious adverse events was higher in the pharmaceutical IA group
  • Pharmaceutical: 3.3 per 1000
  • Procedural, ≤14 weeks, nonhospital: 1.8 per 1000
  • Relative risk (RR) 1.87 (95% CI, 1.44 to 2.43)
  • Absolute risk difference 1.5 per 1000 (95% CI, 0.9 to 2.2)
• Risk of any adverse event (broader outcome) were also higher in the pharmaceutical group
  • Pharmaceutical: 28.9 per 1000
  • Procedural, ≤14 weeks, nonhospital: 12.4 per 1000
  • RR 2.33 (95% CI, 2.11 to 2.57)
  • Absolute risk difference 16.5 per 1000 (95% CI, 14.5 to 18.4)

Comparison 2

• There was no difference in risk of serious adverse events between the groups
  • Pharmaceutical: 3.4 per 1000
  • Procedural, ≤9 weeks, hospital: 3.3 per 1000
  • RR 1.04 (95% CI, 0.61 to 1.78)
• Risk of any adverse event was slightly higher in the pharmaceutical group
  • Pharmaceutical: 31.2 per 1000
  • Procedural, ≤9 weeks, hospital: 24.9 per 1000
  • RR 1.25 (95% CI, 1.04 to 1.51)

CONCLUSION:

• Serious adverse events are rare for induced abortions, but do occur more frequently after pharmaceutical vs procedural approach
• This risk is highest for less serious adverse events

The authors state

The current findings underscore the apparent overall short-term safety of accessible first-trimester IA, especially for SAEs, which are very rare

In conclusion, although short-term adverse events occur more often after mifepristone–misoprostol IA than procedural IA, the risk for serious adverse outcomes is very small

Learn More – Primary Sources:

Short-Term Adverse Outcomes After Mifepristone–Misoprostol Versus Procedural Induced Abortion: A Population-Based Propensity-Weighted Study

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