BACKGROUND AND PURPOSE:

• Chen et al. (BJOG, 2018) sought to determine whether maternal aspirin use during pregnancy is associated with childhood blood pressure

METHODS:

• Secondary analysis of the Collaborative Perinatal Project
  • Prospective cohort study of singleton births
  • Maternal and child health data | 12 US academic medical centers (1959 – 1976)
  • Exposure: Within 4 weeks before LMP | During pregnancy
• Primary outcome: Offspring blood pressure at age 7 years
• Data on covariates that could impart bias were also collected (including pregnancy outcomes such as SGA)
• Linear and multivariate logistic regression analysis was used to draw associations

RESULTS:

• 15,793 women were exposed to aspirin
• In utero aspirin exposure demonstrated the following offspring BP associations at 7 years of age
  • High systolic blood pressure (SBP):  Risk reduction of 11% (95% CI, 0.85– 0.93)
  • High diastolic blood pressure (DBP): Risk reduction of 20% (95% CI, 0.76–0.84)
  • Mean decrease of 0.62 mmHg for SBP and 1.04 mmHg for DBP at 7 years of age
• Compared with children born to mothers without aspirin exposure, those whose mothers were exposed to aspirin for at least 7 days during pregnancy had approximately
  • 10% reduced risk of high SBP
  • 27% reduced risk of high DBP
  • Mean reduction of 0.61 and 1.27 mmHg in SBP and DBP at 7 years of age
  • Risk reduction appears to be independent of maternal hypertensive disorders
• The earlier the aspirin exposure occurred during pregnancy, the lower the risk of elevated childhood high blood pressure
  • Dose-response effect seen based on number of days of exposure
  • Risk reduction effect was consistent across all trimesters

CONCLUSION:

• Limitations of this study include
  • Lack of dosage information (and may likely be typical therapeutic and not low dose, based years of the original study)
  • Lack of indications for aspirin use
• Study strengths include large cohort size and multiple data points with 7 year follow up of offspring  
• In utero exposure to aspirin decreased risk of high childhood blood pressure
• More traditional risk factors for cardiovascular risks such as BMI were not as strongly associated with elevated BP, suggesting that aspirin may exert independent effects on placental vascularization or epigenetic mechanisms

Learn More – Primary Sources:

Association of intrauterine exposure to aspirin and blood pressure at 7 years of age: a secondary analysis

Related ObG Topics:

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

ASPRE Trial: A Combined Risk Algorithm and Use of Aspirin to Prevent Preterm Preeclampsia

Does Low Dose Aspirin Reduce the Risk of Spontaneous Preterm Birth?