Alerts

Should You Consider Aspirin Treatment for Women at Risk for Preeclampsia? ACOG and USPSTF Recommendations

FINDINGS:

ACOG and SMFM have released guidance, stating that they “support the USPSTF guideline criteria for prevention of preeclampsia” on the use of low-dose aspirin during pregnancy to prevent preeclampsia. When indicated, low-dose aspirin should be started between 12 to 28 weeks and continued until delivery. Optimally, aspirin usage should begin <16 weeks.

Offer low-dose aspirin (81 mg/day) to women with ≥1 high risk factors for preeclampsia, which include
- History of preeclampsia, especially if accompanied by an adverse outcome
- Multifetal gestation
- Chronic hypertension
- Diabetes (Type 1 or Type 2)
- Renal disease
- Autoimmune disease (for example, systematic lupus erythematosus, antiphospholipid syndrome)

Consider Prophylaxis

Offer low-dose aspirin (81 mg/day) to women with >1 moderate risk factors for preeclampsia, which include
- Nulliparity
- Obesity (BMI >30)
- Personal history
  - low birthweight
  - SGA
  - Previous adverse pregnancy outcome
- Family history of preeclampsia
  - Sister or mother
- Social and demographic characteristics
  - African American race | low socioeconomic status
- Maternal age ≥35 years
- >10 year interpregnancy interval

Not Recommended Without Preeclampsia Risk Factors

Insufficient Evidence
- Prior unexplained stillbirth (insufficient evidence)
- Prevention of fetal growth restriction
- Prevention of spontaneous PTB
No Benefit
- Prevention of early pregnancy loss

USPSTF Guidance

The systematic review (Ann Intern Med, 2014), performed on behalf of the USPSTF, demonstrated the following benefits for women at risk for preeclampsia
- 14% risk reduction for preterm birth (< 37 weeks)
- 20% risk reduction for IUGR
- Increase in average birthweight of 130 g
- 24% risk reduction for preeclampsia
- Only 1 paper had follow up (18 months) on children; no developmental harms were identified
Harms
- No harms from low-dose aspirin were identified, however some events were sufficiently rare that possible negative outcomes from aspirin use, such as abruption, cannot be completely ruled out
USPSTF updated recommendations
- Based on the above findings, the USPSTF recommends providers offer low-dose aspirin to women at high risk for preeclampsia (‘B’ grade’ – offer or provide this service)

KEY POINTS:

The USPSTF states that “the harms of low-dose aspirin in pregnancy are considered to be no greater than small”
Risk factors used for ACOG/SMFM recommendations only include factors obtained from the medical record
- Uterine artery Doppler ultrasonography and biochemical markers are not included
- ACOG/SMFM acknowledge that other studies, in particular the ASPRE trial (see ‘Related ObG Topics’ below), have incorporated ultrasound and maternal serum markers as well as doses >81 mg, but state

Further, the screening algorithm used includes first-trimester serum markers, including placental growth factor and pregnancy-associated plasma protein-A, as well as uterine artery dopplers, which limits the generalizability to a U.S. population. Therefore, a higher dose or doubling of the available 81-mg dose cannot be recommended at this time.