Only 25-50% of high-risk pregnant women actually receive the low-dose aspirin that could prevent their preeclampsia, because the screening method itself misses 59% of cases

Low-dose aspirin (81 mg daily), started before 16 weeks of gestation, reduces the risk of preeclampsia by 24% in high-risk women. ACOG, the USPSTF, and SMFM all recommend it. The evidence is clear, the intervention is cheap (under $10 for the entire pregnancy), and it is safe. Yet the Society for Maternal-Fetal Medicine has identified that fewer than 25-50% of eligible patients actually receive aspirin. Even after targeted quality improvement interventions, one initiative found prescription rates only rose from 30% to 46%. The drug that could prevent preeclampsia in thousands of women per year is sitting on pharmacy shelves because the system fails to get it prescribed. The problem starts with screening. ACOG's current screening approach uses a checklist of maternal risk factors (prior preeclampsia, chronic hypertension, diabetes, obesity, first pregnancy, age over 35, etc.). A study comparing this approach to first-trimester biomarker-based screening found that ACOG's method identifies only 41% of women who will develop preterm preeclampsia — with a 64% screen-positive rate. That means the screening is simultaneously too broad (flagging 64% of women) and too narrow (missing 59% of actual preeclampsia cases). Providers, faced with a recommendation to prescribe aspirin to the majority of their patients, experience recommendation fatigue and start making ad hoc judgments about who 'really' needs it. The deeper structural issue is that first-trimester screening for preeclampsia using biomarkers and uterine artery Doppler (the FMF algorithm used widely in Europe) dramatically outperforms the risk-factor checklist, but it requires a specific blood test and ultrasound protocol that most U.S. obstetric practices are not set up to perform. The American healthcare system screens for Down syndrome in the first trimester with sophisticated blood tests and ultrasound, but does not apply the same approach to preeclampsia — a condition that kills far more mothers. The result is a screening-to-treatment pipeline that leaks at every stage: bad screening leads to poor identification, poor identification leads to low prescription rates, and low prescription rates mean thousands of preventable preeclampsia cases occur every year.