BACKGROUND AND PURPOSE:

• Low-dose aspirin prior to 16 weeks can reduce preeclampsia risk in at-risk pregnancies
• There is still limited understanding as to how aspirin may work in low-risk women in general
  • Research could help explain potential impact in preventing placental pathology
• Mone et al. (Am J Perinatol., 2019) sought to determine the effect of aspirin use in low-risk pregnancy on
  • PAPP-A and placental-like growth factor (PLGF)
  • Urinary albumin-to-creatinine ratio (ACR) and blood pressure
  • Fetal growth
  • Placental histopathology and fetal-to-placental weight (FPW)

METHODS:

• Secondary analysis of a randomized trial (RCT)
  • TEST study: Trial of low-dose aspirin with an Early Screening Test
  • RCT to assess aspirin and effect on preeclampsia and growth restriction
  • Feasibility study, not powered for efficacy
• TEST study methods: 546 low-risk nulliparous women were randomized at 11 weeks to receive one of the following
  • Routine aspirin 75 mg once daily from 11 until 36 weeks (n = 179)
  • No aspirin (n = 183)
  • Aspirin administered based on FMF screening test (n=184)
    • FMF inputs: Maternal history | Blood pressure | Uterine artery Doppler | PAPP-A and PLGF levels
  • Blood pressure | PAPP-A | PLGF | ACR
    • Baseline
    • Repeated at 9 to 10 weeks following aspirin
  • Fetal Growth studies
  • Gross and histopathological placental analyses
  • Multiple linear regression model used to compare aspirin vs nonaspirin-taking women
    • Controlled for maternal weight, ethnicity, smoking status, and ovulation-induced conception

RESULTS:

• In current study, 445 subjects were included
  • Aspirin 163 | 282 no aspirin
• Compared to the placebo group, the aspirin group had greater
  • Fetal-to-placental weight ratio: 7.5 vs. 7.3 (p = 0.045)
  • Change in EFW between second and third trimesters: 1,624.5 g vs. 1,606.2g (p = 0.042)
• However, there was no significant difference in birth weight or fetal growth restriction
• Aspirin did not significantly impact on change in serum or urine preeclampsia biomarkers, maternal blood pressure, or placental histopathology

CONCLUSION:

• Study limitations include
  • Aspirin dose (may be too low)
  • Non-blinded design
  • 8% of aspirin subjects came from higher risk group ‘3’ (FMF criteria)
• Strengths include RCT design and methods
• Aspirin use in low-risk pregnancy did not significantly impact preeclampsia biomarkers, fetal growth, or placental pathology

Learn More – Primary Sources:

Evaluation of the Effect of Low-Dose Aspirin on Biochemical and Biophysical Biomarkers for Placental Disease in Low-Risk Pregnancy: Secondary Analysis of a Multicenter RCT.

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