The Silent Crisis: Rising Rates of Preeclampsia
Preeclampsia remains one of the most formidable challenges in modern obstetrics. Characterized by a sudden onset of high blood pressure and potential damage to organ systems, most often the liver and kidneys, it affects approximately 8% of all pregnancies. However, the statistics in the United States have taken an alarming turn. Between 2007 and 2019, the rates of hypertensive disorders of pregnancy, including both gestational hypertension and preeclampsia, essentially doubled. This trend correlates with a disturbing rise in maternal mortality, placing the United States in a precarious position with the highest rates among high-income nations.
In response to this escalating health crisis, the medical community has sought reliable ways to predict who is at risk and how to intervene before the condition becomes life-threatening. One of the primary tools in this effort is the risk-based approach developed by the US Preventive Services Task Force (USPSTF). Their guidelines recommend identifying at-risk individuals based on clinical and demographic factors and initiating low-dose aspirin prophylaxis (AP) starting at 12 weeks of gestation.
A Real-World Scenario: Sarah’s Journey
To understand how these guidelines function in practice, consider the case of Sarah Miller, a 32-year-old marketing executive pregnant with her first child. Sarah is healthy, but she falls into what the USPSTF calls a “moderate risk” category because this is her first pregnancy and her Body Mass Index (BMI) is 31, which is classified as obese.
During her 12-week checkup, Sarah’s obstetrician notes these factors. Under the USPSTF guidelines, having two moderate risk factors—nulliparity (first pregnancy) and obesity—makes Sarah a candidate for low-dose aspirin. However, like many patients in a busy clinical setting, Sarah might not receive this recommendation unless the screening process is rigorous. In the study we are examining, nearly 70% of participants fell into a similar moderate-risk category, yet the consistency of aspirin recommendations varied wildly. Sarah’s story represents millions of pregnant individuals navigating a complex system where risk stratification is essential but implementation remains inconsistent.
What is the USPSTF Risk-Based Approach?
The USPSTF guidelines categorize pregnant individuals into high, moderate, or low risk for preeclampsia. This stratification is crucial because it dictates the preventative strategy, specifically the use of aspirin.
Individuals are considered high risk if they have at least one of the following:
– History of preeclampsia in a previous pregnancy
– Multifetal gestation (twins, triplets, etc.)
– Chronic hypertension
– Type 1 or 2 diabetes
– Renal (kidney) disease
– Autoimmune diseases (like systemic lupus erythematosus or antiphospholipid syndrome)
Moderate risk factors include:
– Nulliparity (first birth)
– Obesity (BMI > 30)
– Family history of preeclampsia
– Advanced maternal age (35 or older)
– Socioeconomic factors or personal history factors (such as African American race or low income, which are often markers for systemic health disparities)
Deep Dive: The McElrath et al. Study
A recent prospective cohort study, led by McElrath and colleagues and published across 11 medical centers, sought to evaluate just how well these USPSTF criteria work in a diverse, real-world population. The study included 5,684 participants between 2020 and 2023. This racially and geographically diverse group provided a clear window into how risk is assessed and how aspirin is prescribed.
The findings were illuminating. Out of the total population:
– 12% were diagnosed with preeclampsia.
– 11% had gestational hypertension that progressed to preeclampsia.
– 18.5% were classified as high risk.
– 70.3% were classified as moderate risk.
– Only 11.2% were classified as low risk.
This distribution highlights a significant reality in modern prenatal care: the vast majority of pregnant individuals (nearly 90%) have at least one risk factor that could potentially warrant medical intervention or at least closer monitoring.
Scientific and Clinical Evidence: What the Data Tell Us
The study confirmed that high-risk factors are indeed potent predictors of the condition. Individuals with a prior history of preeclampsia saw a risk ratio (RR) of 1.44, meaning they were 44% more likely to develop the condition again. Chronic hypertension was also a major driver, with a risk ratio of 1.26.
However, the data regarding moderate risk factors were more nuanced. When researchers broke down the moderate-risk group into those with only one factor versus those with two or more, the statistical significance of these factors as predictors began to wane. Surprisingly, while incidence varied by race, the study found that racial categories themselves were not associated with an increased risk of preeclampsia once other clinical and demographic factors were accounted for. This suggests that the physiological risk is more closely tied to underlying health conditions and clinical history than to race alone, though systemic factors influencing those health conditions cannot be ignored.
The Aspirin Gap: Bridging the Implementation Divide
One of the most critical aspects of the USPSTF guidelines is the recommendation for low-dose aspirin prophylaxis. Research has shown that aspirin can reduce the risk of preeclampsia by improving blood flow to the placenta and reducing inflammation.
In the McElrath study, however, a significant “implementation gap” was identified. Only about 47% of participants with one or more risk factors received a recommendation for aspirin. Those with the most obvious high-risk factors—such as chronic hypertension or a history of preeclampsia—were the most likely to be told to take aspirin. Those in the moderate-risk categories were frequently overlooked.
Table: USPSTF Risk Stratification and Study Outcomes
| Risk Category | Definition (Examples) | Prevalence in Study | Preeclampsia Association |
| :— | :— | :— | :— |
| High Risk | Prior preeclampsia, Chronic hypertension, Diabetes | 18.5% | Strong association (RR 1.26 – 1.44) |
| Moderate 2+ | Two or more moderate factors (e.g., Age 35+ and Obesity) | 35.9% | Weakly associated |
| Moderate 1 | Only one moderate factor (e.g., First pregnancy) | 34.4% | Weakly associated |
| Low Risk | No high or moderate risk factors identified | 11.2% | Baseline risk |
Expert Insights and Commentary
“The USPSTF criteria are a solid starting point, but they are not a perfect sieve,” says Dr. James Thompson, a specialist in maternal-fetal medicine not involved in the study. “What this research tells us is that while we are good at identifying the highest-risk patients, we are still struggling with the ‘moderate’ middle. We need to move toward a more personalized approach that perhaps combines these clinical markers with newer biomarkers or ultrasound findings.”
Dr. Thompson also emphasizes the importance of the aspirin recommendation. “Aspirin is a low-cost, low-risk intervention. The fact that fewer than half of at-risk women in this study were recommended aspirin suggests we have a major opportunity to improve outcomes simply by adhering more strictly to existing guidelines.”
Conclusion
The USPSTF risk assessment tool remains a vital component of prenatal care in the United States. It effectively identifies those at the highest risk, allowing for early intervention. However, its utility in the moderate-risk population is less clear, and the clinical application of its recommendations—specifically regarding aspirin—is currently insufficient.
For pregnant individuals, the takeaway is clear: be proactive. If you have any of the risk factors mentioned—even if they seem minor, like it being your first pregnancy or being over age 35—discuss the potential benefits of low-dose aspirin with your healthcare provider. For clinicians, the study serves as a call to action to standardize risk assessment and ensure that every patient who meets the criteria for prophylaxis is given the opportunity to protect themselves and their baby.
References
McElrath TF, Jeyabalan A, Khodursky A, Moe AB, Lee M, Jain M, Goetzl L, Sutton EF, Simmons PM, Saade GR, Saad A, Pacheco LD, Park-Hwang E, Frolova A, Carter EB, Collier AY, Kiefer DG, Berghella V, Boelig RC, Elovitz MA, Gyamfi-Bannerman C, Biggio JR, Rood K, Grobman WA, Haverty C, Rasmussen M. Utility of the US Preventive Services Task Force for Preeclampsia Risk Assessment and Aspirin Prophylaxis. Obstet Gynecol Surv. 2026 Jan 1;81(1):5-7. doi: 10.1097/01.ogx.0001179548.39409.03. Epub 2026 Jan 19. PMID: 41557918.
