BACKGROUND AND PURPOSE:

• ACOG recommends 81 mg of aspirin per day, initiated between 12 and 16 weeks, to prevent preeclampsia in high risk groups, including those with chronic hypertension
• Banala et al. (AJOG, 2020) assessed the effectiveness of aspirin for the prevention of superimposed preeclampsia and other adverse maternal and neonatal outcomes in women with chronic hypertension before and after the 2016 guideline was released

METHODS:

• Retrospective cohort study (2014 to 2018)
• Participants
  • Women with chronic hypertension who delivered at a single hospital
• Exposures
  • Before ACOG 2016 guidelines
  • After ACOG 2016 guidelines
• Data analysis
  • Subgroup analysis history of preeclampsia, and pregestational diabetes
• Primary outcome
  • Incidence of superimposed preeclampsia
• Secondary outcomes
  • Superimposed preeclampsia with or without severe features
  • Small for gestational age (SGA)
  • Preterm birth <37 weeks

RESULTS:

• 457 pregnant women
  • Before 2016 guidelines group: 254 women
    • Offered daily aspirin: 7.0%
  • After 2016 guidelines group: 203 women
    • Offered daily aspirin: 70%
  • There were no significant differences in maternal demographics
• There was no significant difference in overall incidence of superimposed preeclampsia between the two groups (P = 0.79)
  • Before group: 34.3%
  • After group: 35.5%
• Superimposed preeclampsia without severe features was decreased in the post ACOG 2016 group (p<0.01)
  • Before group: 12.6%
  • After group: 4.4%
• Superimposed preeclampsia with severe features was significantly increased in the after group (P = 0.02)
  • Before group: 21.7%
  • After group: 31.0%
• There were no significant differences in SGA neonates or preterm birth between groups
• Subgroup analyses did not alter the results

CONCLUSION:

• After the 2016 ACOG guidelines were implemented, 70% of the investigated cohort was offered aspirin
• There were no significant differences in the incidence of superimposed preeclampsia, severe features, SGA, or preterm birth before and after the implementation of these new guidelines
• The authors suggest the increase seen in preeclampsia with severe features in the post-ACOG group may be

…secondary to a learning curve after the publication of the 2013 ACOG guidelines with new diagnostic criteria and management for superimposed preeclampsia and superimposed preeclampsia with severe features

We hypothesize possible underdiagnosis in the subsequent few years (pre-ACOG group)

Learn More – Primary Sources:

Impact of the ACOG guideline regarding low-dose aspirin for prevention of superimposed preeclampsia in women with chronic hypertension

Related ObG Topics:

Aspirin Treatment for Women at Risk for Preeclampsia – ACOG and USPSTF Recommendations  

Is Aspirin for Early Preeclampsia Prophylaxis Cost-Effective?

Does Aspirin for Preeclampsia Risk Reduction Affect Biomarkers or Fetal Growth?